Atoms- Basic Units of Matter
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Transcript
Atoms- Basic Units of Matter
What is Matter
bull Matter is anything that has mass and
takes up space
bull Things you can see (chair)
bull Things you canrsquot see (air)
bull All matter is made of atoms
bull Matter or Energy
bull Energy- Light Sound Heat Fire
What is an Atom
bull It is a very small particle that makes up all
matter
bull Atoms are so small that there are 5 million
atoms in one period
Democritus
bull He was a Greek philosopher
bull He wanted to know if you could cut something in frac12 enough times that you could have one piece left that was ldquoun-cut-ablerdquo
bull He was the first person to use the word ldquoatomrdquo that comes from the Greek word ldquoAtomardquo which means ldquoIndivisiblerdquo (you can not divide it)
bull Atomos - uncuttable
Parts of an Atom
bull Proton - Positively charged particle in the
nucleus of an atom
bull Neutron- A neutral particle (NO charge) in
the nucleus
bull Neutron Neutral No charge
bull Electron- A negatively charged particle
that moves in the space around the
nucleus
An Atom Model of Lithium(Pg 175 textbook) Finish drawing for homework
Size of Atoms
bull Protons have a mass of about 1
bull Neutrons have a mass of about 1
bull Electrons are 2000 times smaller than a proton or neutron (12000th)
bull If you could make a model of the nucleus think of a proton and neutron about the size of an apple and orange
bull At this size an electron would be about the size of a fruit fly
Size of Atom
bull Even though an atom is small it is mostly
empty space
bull If you could make a model of an atom the
size of a football field The nucleus of an
atom would be the size of an ant
Standard 3a ndash The Structure of an Atom
bullA typical single strand of human hair is
10 million carbon atoms wide
bullA single drop of water contains 2
sextillion (2x1021) atoms of oxygen and
twice as many hydrogen atoms
bullWe are able to see the surface of atoms
by using a scanning tunneling electron
microscope
Whatrsquos Inside
bull How do we know what is inside of an
atom
Mystery Bags (Pg 2 Spiral)
bull (These are directions- you donrsquot have to write
this) You will be given a paper bag that has
something unknown inside Your job is to guess
what it is WITHOUT looking in the bag (The
bag stays closed at all times)
bull You can touch it smell it listen to it etc Is it
hard Soft Shape Thickness Write down all
of your observations
bull Then guess what it might be
Standard 3a ndash The Structure of an
Atom
Question How do we know what atoms are
made of if we can only see the outside
Atomic Model
Answer Over many
years scientists
have developed a
model based on
indirect experiments
on matter
History of the Atom (pg 3 spiral)
bull Who was responsible for our path of
understanding the atom
bull We are still learning about the atom today
Dalton 1766-1844
bull He thought an atom was a simple neutral
sphere of indivisible matter that was the
same throughout
bull Atoms of different elements were different
from one another (gold vs iron)
bull All gold was made from gold atoms and all
iron was made from iron atoms etc
bull Pg 178TB Daltonrsquos atomic symbols
Thomson 1897
bull In the 1800rsquos JJ Thomson discovered electronsbull httphigheredmcgraw-
hillcomolcwebcgipluginpopcgiit=swf100100sitesdlfree007251264411735401_Cathode_Ray_TubeswfCathode20Ray20Tube
bull He was able to bend the light of a cathode ray with magnets The ray bent towards the positive plate so he knew that there was a negative charge (He called that negative charge an electron)
bull There must be a positive charge to balance this because atoms are neutral
bull Chocolate chip cookie model (Positive dough with negative chocolate chips throughout)
bull He concluded that atoms can be divided
Rutherford 1911
bull Discovered the nucleus (positive charge) Protons
bull Gold foil experimentbull httpwwwmhhecomphysscichemistryessentialchemistryflashruther14swf
bull Positively charged Alpha particles were shot at a
really thin piece of gold foil
bull Some particles went through the foil some went
off to the sides and a few bounced back
bull He compared the ones that bounced back as
amazing as if a cannon ball bouncing off of a
kleenex (approx 1 in 8000)
Chadwick 1932
bull Discovered neutrons
bull Working with the cathode ray they (Rutherford
and his students) looked for protons (+1 charge)
and knew the approximate mass of elements
bull They could not account for all of the mass so he
predicted that there was a neutral particle in the
nucleus with the proton and named it a neutron
bull neutron- neutral-no charge
Bohr
bull Electrons are arranged in energy levels
bull The closer energy levels hold just a few and the outer levels hold more
bull Just like a person stands on a ladder and has to move to the next step (rung) an electron can only jump to the next energy level
bull He discovered this working with spectral lines in a single wavelength of light
Todayrsquos Model
bull Electrons occupy a space around the
nucleus in the electron cloud
bull They do not orbit like planets around the
sun but move rapidly from one place to
another
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
What is Matter
bull Matter is anything that has mass and
takes up space
bull Things you can see (chair)
bull Things you canrsquot see (air)
bull All matter is made of atoms
bull Matter or Energy
bull Energy- Light Sound Heat Fire
What is an Atom
bull It is a very small particle that makes up all
matter
bull Atoms are so small that there are 5 million
atoms in one period
Democritus
bull He was a Greek philosopher
bull He wanted to know if you could cut something in frac12 enough times that you could have one piece left that was ldquoun-cut-ablerdquo
bull He was the first person to use the word ldquoatomrdquo that comes from the Greek word ldquoAtomardquo which means ldquoIndivisiblerdquo (you can not divide it)
bull Atomos - uncuttable
Parts of an Atom
bull Proton - Positively charged particle in the
nucleus of an atom
bull Neutron- A neutral particle (NO charge) in
the nucleus
bull Neutron Neutral No charge
bull Electron- A negatively charged particle
that moves in the space around the
nucleus
An Atom Model of Lithium(Pg 175 textbook) Finish drawing for homework
Size of Atoms
bull Protons have a mass of about 1
bull Neutrons have a mass of about 1
bull Electrons are 2000 times smaller than a proton or neutron (12000th)
bull If you could make a model of the nucleus think of a proton and neutron about the size of an apple and orange
bull At this size an electron would be about the size of a fruit fly
Size of Atom
bull Even though an atom is small it is mostly
empty space
bull If you could make a model of an atom the
size of a football field The nucleus of an
atom would be the size of an ant
Standard 3a ndash The Structure of an Atom
bullA typical single strand of human hair is
10 million carbon atoms wide
bullA single drop of water contains 2
sextillion (2x1021) atoms of oxygen and
twice as many hydrogen atoms
bullWe are able to see the surface of atoms
by using a scanning tunneling electron
microscope
Whatrsquos Inside
bull How do we know what is inside of an
atom
Mystery Bags (Pg 2 Spiral)
bull (These are directions- you donrsquot have to write
this) You will be given a paper bag that has
something unknown inside Your job is to guess
what it is WITHOUT looking in the bag (The
bag stays closed at all times)
bull You can touch it smell it listen to it etc Is it
hard Soft Shape Thickness Write down all
of your observations
bull Then guess what it might be
Standard 3a ndash The Structure of an
Atom
Question How do we know what atoms are
made of if we can only see the outside
Atomic Model
Answer Over many
years scientists
have developed a
model based on
indirect experiments
on matter
History of the Atom (pg 3 spiral)
bull Who was responsible for our path of
understanding the atom
bull We are still learning about the atom today
Dalton 1766-1844
bull He thought an atom was a simple neutral
sphere of indivisible matter that was the
same throughout
bull Atoms of different elements were different
from one another (gold vs iron)
bull All gold was made from gold atoms and all
iron was made from iron atoms etc
bull Pg 178TB Daltonrsquos atomic symbols
Thomson 1897
bull In the 1800rsquos JJ Thomson discovered electronsbull httphigheredmcgraw-
hillcomolcwebcgipluginpopcgiit=swf100100sitesdlfree007251264411735401_Cathode_Ray_TubeswfCathode20Ray20Tube
bull He was able to bend the light of a cathode ray with magnets The ray bent towards the positive plate so he knew that there was a negative charge (He called that negative charge an electron)
bull There must be a positive charge to balance this because atoms are neutral
bull Chocolate chip cookie model (Positive dough with negative chocolate chips throughout)
bull He concluded that atoms can be divided
Rutherford 1911
bull Discovered the nucleus (positive charge) Protons
bull Gold foil experimentbull httpwwwmhhecomphysscichemistryessentialchemistryflashruther14swf
bull Positively charged Alpha particles were shot at a
really thin piece of gold foil
bull Some particles went through the foil some went
off to the sides and a few bounced back
bull He compared the ones that bounced back as
amazing as if a cannon ball bouncing off of a
kleenex (approx 1 in 8000)
Chadwick 1932
bull Discovered neutrons
bull Working with the cathode ray they (Rutherford
and his students) looked for protons (+1 charge)
and knew the approximate mass of elements
bull They could not account for all of the mass so he
predicted that there was a neutral particle in the
nucleus with the proton and named it a neutron
bull neutron- neutral-no charge
Bohr
bull Electrons are arranged in energy levels
bull The closer energy levels hold just a few and the outer levels hold more
bull Just like a person stands on a ladder and has to move to the next step (rung) an electron can only jump to the next energy level
bull He discovered this working with spectral lines in a single wavelength of light
Todayrsquos Model
bull Electrons occupy a space around the
nucleus in the electron cloud
bull They do not orbit like planets around the
sun but move rapidly from one place to
another
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
What is an Atom
bull It is a very small particle that makes up all
matter
bull Atoms are so small that there are 5 million
atoms in one period
Democritus
bull He was a Greek philosopher
bull He wanted to know if you could cut something in frac12 enough times that you could have one piece left that was ldquoun-cut-ablerdquo
bull He was the first person to use the word ldquoatomrdquo that comes from the Greek word ldquoAtomardquo which means ldquoIndivisiblerdquo (you can not divide it)
bull Atomos - uncuttable
Parts of an Atom
bull Proton - Positively charged particle in the
nucleus of an atom
bull Neutron- A neutral particle (NO charge) in
the nucleus
bull Neutron Neutral No charge
bull Electron- A negatively charged particle
that moves in the space around the
nucleus
An Atom Model of Lithium(Pg 175 textbook) Finish drawing for homework
Size of Atoms
bull Protons have a mass of about 1
bull Neutrons have a mass of about 1
bull Electrons are 2000 times smaller than a proton or neutron (12000th)
bull If you could make a model of the nucleus think of a proton and neutron about the size of an apple and orange
bull At this size an electron would be about the size of a fruit fly
Size of Atom
bull Even though an atom is small it is mostly
empty space
bull If you could make a model of an atom the
size of a football field The nucleus of an
atom would be the size of an ant
Standard 3a ndash The Structure of an Atom
bullA typical single strand of human hair is
10 million carbon atoms wide
bullA single drop of water contains 2
sextillion (2x1021) atoms of oxygen and
twice as many hydrogen atoms
bullWe are able to see the surface of atoms
by using a scanning tunneling electron
microscope
Whatrsquos Inside
bull How do we know what is inside of an
atom
Mystery Bags (Pg 2 Spiral)
bull (These are directions- you donrsquot have to write
this) You will be given a paper bag that has
something unknown inside Your job is to guess
what it is WITHOUT looking in the bag (The
bag stays closed at all times)
bull You can touch it smell it listen to it etc Is it
hard Soft Shape Thickness Write down all
of your observations
bull Then guess what it might be
Standard 3a ndash The Structure of an
Atom
Question How do we know what atoms are
made of if we can only see the outside
Atomic Model
Answer Over many
years scientists
have developed a
model based on
indirect experiments
on matter
History of the Atom (pg 3 spiral)
bull Who was responsible for our path of
understanding the atom
bull We are still learning about the atom today
Dalton 1766-1844
bull He thought an atom was a simple neutral
sphere of indivisible matter that was the
same throughout
bull Atoms of different elements were different
from one another (gold vs iron)
bull All gold was made from gold atoms and all
iron was made from iron atoms etc
bull Pg 178TB Daltonrsquos atomic symbols
Thomson 1897
bull In the 1800rsquos JJ Thomson discovered electronsbull httphigheredmcgraw-
hillcomolcwebcgipluginpopcgiit=swf100100sitesdlfree007251264411735401_Cathode_Ray_TubeswfCathode20Ray20Tube
bull He was able to bend the light of a cathode ray with magnets The ray bent towards the positive plate so he knew that there was a negative charge (He called that negative charge an electron)
bull There must be a positive charge to balance this because atoms are neutral
bull Chocolate chip cookie model (Positive dough with negative chocolate chips throughout)
bull He concluded that atoms can be divided
Rutherford 1911
bull Discovered the nucleus (positive charge) Protons
bull Gold foil experimentbull httpwwwmhhecomphysscichemistryessentialchemistryflashruther14swf
bull Positively charged Alpha particles were shot at a
really thin piece of gold foil
bull Some particles went through the foil some went
off to the sides and a few bounced back
bull He compared the ones that bounced back as
amazing as if a cannon ball bouncing off of a
kleenex (approx 1 in 8000)
Chadwick 1932
bull Discovered neutrons
bull Working with the cathode ray they (Rutherford
and his students) looked for protons (+1 charge)
and knew the approximate mass of elements
bull They could not account for all of the mass so he
predicted that there was a neutral particle in the
nucleus with the proton and named it a neutron
bull neutron- neutral-no charge
Bohr
bull Electrons are arranged in energy levels
bull The closer energy levels hold just a few and the outer levels hold more
bull Just like a person stands on a ladder and has to move to the next step (rung) an electron can only jump to the next energy level
bull He discovered this working with spectral lines in a single wavelength of light
Todayrsquos Model
bull Electrons occupy a space around the
nucleus in the electron cloud
bull They do not orbit like planets around the
sun but move rapidly from one place to
another
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
Democritus
bull He was a Greek philosopher
bull He wanted to know if you could cut something in frac12 enough times that you could have one piece left that was ldquoun-cut-ablerdquo
bull He was the first person to use the word ldquoatomrdquo that comes from the Greek word ldquoAtomardquo which means ldquoIndivisiblerdquo (you can not divide it)
bull Atomos - uncuttable
Parts of an Atom
bull Proton - Positively charged particle in the
nucleus of an atom
bull Neutron- A neutral particle (NO charge) in
the nucleus
bull Neutron Neutral No charge
bull Electron- A negatively charged particle
that moves in the space around the
nucleus
An Atom Model of Lithium(Pg 175 textbook) Finish drawing for homework
Size of Atoms
bull Protons have a mass of about 1
bull Neutrons have a mass of about 1
bull Electrons are 2000 times smaller than a proton or neutron (12000th)
bull If you could make a model of the nucleus think of a proton and neutron about the size of an apple and orange
bull At this size an electron would be about the size of a fruit fly
Size of Atom
bull Even though an atom is small it is mostly
empty space
bull If you could make a model of an atom the
size of a football field The nucleus of an
atom would be the size of an ant
Standard 3a ndash The Structure of an Atom
bullA typical single strand of human hair is
10 million carbon atoms wide
bullA single drop of water contains 2
sextillion (2x1021) atoms of oxygen and
twice as many hydrogen atoms
bullWe are able to see the surface of atoms
by using a scanning tunneling electron
microscope
Whatrsquos Inside
bull How do we know what is inside of an
atom
Mystery Bags (Pg 2 Spiral)
bull (These are directions- you donrsquot have to write
this) You will be given a paper bag that has
something unknown inside Your job is to guess
what it is WITHOUT looking in the bag (The
bag stays closed at all times)
bull You can touch it smell it listen to it etc Is it
hard Soft Shape Thickness Write down all
of your observations
bull Then guess what it might be
Standard 3a ndash The Structure of an
Atom
Question How do we know what atoms are
made of if we can only see the outside
Atomic Model
Answer Over many
years scientists
have developed a
model based on
indirect experiments
on matter
History of the Atom (pg 3 spiral)
bull Who was responsible for our path of
understanding the atom
bull We are still learning about the atom today
Dalton 1766-1844
bull He thought an atom was a simple neutral
sphere of indivisible matter that was the
same throughout
bull Atoms of different elements were different
from one another (gold vs iron)
bull All gold was made from gold atoms and all
iron was made from iron atoms etc
bull Pg 178TB Daltonrsquos atomic symbols
Thomson 1897
bull In the 1800rsquos JJ Thomson discovered electronsbull httphigheredmcgraw-
hillcomolcwebcgipluginpopcgiit=swf100100sitesdlfree007251264411735401_Cathode_Ray_TubeswfCathode20Ray20Tube
bull He was able to bend the light of a cathode ray with magnets The ray bent towards the positive plate so he knew that there was a negative charge (He called that negative charge an electron)
bull There must be a positive charge to balance this because atoms are neutral
bull Chocolate chip cookie model (Positive dough with negative chocolate chips throughout)
bull He concluded that atoms can be divided
Rutherford 1911
bull Discovered the nucleus (positive charge) Protons
bull Gold foil experimentbull httpwwwmhhecomphysscichemistryessentialchemistryflashruther14swf
bull Positively charged Alpha particles were shot at a
really thin piece of gold foil
bull Some particles went through the foil some went
off to the sides and a few bounced back
bull He compared the ones that bounced back as
amazing as if a cannon ball bouncing off of a
kleenex (approx 1 in 8000)
Chadwick 1932
bull Discovered neutrons
bull Working with the cathode ray they (Rutherford
and his students) looked for protons (+1 charge)
and knew the approximate mass of elements
bull They could not account for all of the mass so he
predicted that there was a neutral particle in the
nucleus with the proton and named it a neutron
bull neutron- neutral-no charge
Bohr
bull Electrons are arranged in energy levels
bull The closer energy levels hold just a few and the outer levels hold more
bull Just like a person stands on a ladder and has to move to the next step (rung) an electron can only jump to the next energy level
bull He discovered this working with spectral lines in a single wavelength of light
Todayrsquos Model
bull Electrons occupy a space around the
nucleus in the electron cloud
bull They do not orbit like planets around the
sun but move rapidly from one place to
another
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
Parts of an Atom
bull Proton - Positively charged particle in the
nucleus of an atom
bull Neutron- A neutral particle (NO charge) in
the nucleus
bull Neutron Neutral No charge
bull Electron- A negatively charged particle
that moves in the space around the
nucleus
An Atom Model of Lithium(Pg 175 textbook) Finish drawing for homework
Size of Atoms
bull Protons have a mass of about 1
bull Neutrons have a mass of about 1
bull Electrons are 2000 times smaller than a proton or neutron (12000th)
bull If you could make a model of the nucleus think of a proton and neutron about the size of an apple and orange
bull At this size an electron would be about the size of a fruit fly
Size of Atom
bull Even though an atom is small it is mostly
empty space
bull If you could make a model of an atom the
size of a football field The nucleus of an
atom would be the size of an ant
Standard 3a ndash The Structure of an Atom
bullA typical single strand of human hair is
10 million carbon atoms wide
bullA single drop of water contains 2
sextillion (2x1021) atoms of oxygen and
twice as many hydrogen atoms
bullWe are able to see the surface of atoms
by using a scanning tunneling electron
microscope
Whatrsquos Inside
bull How do we know what is inside of an
atom
Mystery Bags (Pg 2 Spiral)
bull (These are directions- you donrsquot have to write
this) You will be given a paper bag that has
something unknown inside Your job is to guess
what it is WITHOUT looking in the bag (The
bag stays closed at all times)
bull You can touch it smell it listen to it etc Is it
hard Soft Shape Thickness Write down all
of your observations
bull Then guess what it might be
Standard 3a ndash The Structure of an
Atom
Question How do we know what atoms are
made of if we can only see the outside
Atomic Model
Answer Over many
years scientists
have developed a
model based on
indirect experiments
on matter
History of the Atom (pg 3 spiral)
bull Who was responsible for our path of
understanding the atom
bull We are still learning about the atom today
Dalton 1766-1844
bull He thought an atom was a simple neutral
sphere of indivisible matter that was the
same throughout
bull Atoms of different elements were different
from one another (gold vs iron)
bull All gold was made from gold atoms and all
iron was made from iron atoms etc
bull Pg 178TB Daltonrsquos atomic symbols
Thomson 1897
bull In the 1800rsquos JJ Thomson discovered electronsbull httphigheredmcgraw-
hillcomolcwebcgipluginpopcgiit=swf100100sitesdlfree007251264411735401_Cathode_Ray_TubeswfCathode20Ray20Tube
bull He was able to bend the light of a cathode ray with magnets The ray bent towards the positive plate so he knew that there was a negative charge (He called that negative charge an electron)
bull There must be a positive charge to balance this because atoms are neutral
bull Chocolate chip cookie model (Positive dough with negative chocolate chips throughout)
bull He concluded that atoms can be divided
Rutherford 1911
bull Discovered the nucleus (positive charge) Protons
bull Gold foil experimentbull httpwwwmhhecomphysscichemistryessentialchemistryflashruther14swf
bull Positively charged Alpha particles were shot at a
really thin piece of gold foil
bull Some particles went through the foil some went
off to the sides and a few bounced back
bull He compared the ones that bounced back as
amazing as if a cannon ball bouncing off of a
kleenex (approx 1 in 8000)
Chadwick 1932
bull Discovered neutrons
bull Working with the cathode ray they (Rutherford
and his students) looked for protons (+1 charge)
and knew the approximate mass of elements
bull They could not account for all of the mass so he
predicted that there was a neutral particle in the
nucleus with the proton and named it a neutron
bull neutron- neutral-no charge
Bohr
bull Electrons are arranged in energy levels
bull The closer energy levels hold just a few and the outer levels hold more
bull Just like a person stands on a ladder and has to move to the next step (rung) an electron can only jump to the next energy level
bull He discovered this working with spectral lines in a single wavelength of light
Todayrsquos Model
bull Electrons occupy a space around the
nucleus in the electron cloud
bull They do not orbit like planets around the
sun but move rapidly from one place to
another
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
An Atom Model of Lithium(Pg 175 textbook) Finish drawing for homework
Size of Atoms
bull Protons have a mass of about 1
bull Neutrons have a mass of about 1
bull Electrons are 2000 times smaller than a proton or neutron (12000th)
bull If you could make a model of the nucleus think of a proton and neutron about the size of an apple and orange
bull At this size an electron would be about the size of a fruit fly
Size of Atom
bull Even though an atom is small it is mostly
empty space
bull If you could make a model of an atom the
size of a football field The nucleus of an
atom would be the size of an ant
Standard 3a ndash The Structure of an Atom
bullA typical single strand of human hair is
10 million carbon atoms wide
bullA single drop of water contains 2
sextillion (2x1021) atoms of oxygen and
twice as many hydrogen atoms
bullWe are able to see the surface of atoms
by using a scanning tunneling electron
microscope
Whatrsquos Inside
bull How do we know what is inside of an
atom
Mystery Bags (Pg 2 Spiral)
bull (These are directions- you donrsquot have to write
this) You will be given a paper bag that has
something unknown inside Your job is to guess
what it is WITHOUT looking in the bag (The
bag stays closed at all times)
bull You can touch it smell it listen to it etc Is it
hard Soft Shape Thickness Write down all
of your observations
bull Then guess what it might be
Standard 3a ndash The Structure of an
Atom
Question How do we know what atoms are
made of if we can only see the outside
Atomic Model
Answer Over many
years scientists
have developed a
model based on
indirect experiments
on matter
History of the Atom (pg 3 spiral)
bull Who was responsible for our path of
understanding the atom
bull We are still learning about the atom today
Dalton 1766-1844
bull He thought an atom was a simple neutral
sphere of indivisible matter that was the
same throughout
bull Atoms of different elements were different
from one another (gold vs iron)
bull All gold was made from gold atoms and all
iron was made from iron atoms etc
bull Pg 178TB Daltonrsquos atomic symbols
Thomson 1897
bull In the 1800rsquos JJ Thomson discovered electronsbull httphigheredmcgraw-
hillcomolcwebcgipluginpopcgiit=swf100100sitesdlfree007251264411735401_Cathode_Ray_TubeswfCathode20Ray20Tube
bull He was able to bend the light of a cathode ray with magnets The ray bent towards the positive plate so he knew that there was a negative charge (He called that negative charge an electron)
bull There must be a positive charge to balance this because atoms are neutral
bull Chocolate chip cookie model (Positive dough with negative chocolate chips throughout)
bull He concluded that atoms can be divided
Rutherford 1911
bull Discovered the nucleus (positive charge) Protons
bull Gold foil experimentbull httpwwwmhhecomphysscichemistryessentialchemistryflashruther14swf
bull Positively charged Alpha particles were shot at a
really thin piece of gold foil
bull Some particles went through the foil some went
off to the sides and a few bounced back
bull He compared the ones that bounced back as
amazing as if a cannon ball bouncing off of a
kleenex (approx 1 in 8000)
Chadwick 1932
bull Discovered neutrons
bull Working with the cathode ray they (Rutherford
and his students) looked for protons (+1 charge)
and knew the approximate mass of elements
bull They could not account for all of the mass so he
predicted that there was a neutral particle in the
nucleus with the proton and named it a neutron
bull neutron- neutral-no charge
Bohr
bull Electrons are arranged in energy levels
bull The closer energy levels hold just a few and the outer levels hold more
bull Just like a person stands on a ladder and has to move to the next step (rung) an electron can only jump to the next energy level
bull He discovered this working with spectral lines in a single wavelength of light
Todayrsquos Model
bull Electrons occupy a space around the
nucleus in the electron cloud
bull They do not orbit like planets around the
sun but move rapidly from one place to
another
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
Size of Atoms
bull Protons have a mass of about 1
bull Neutrons have a mass of about 1
bull Electrons are 2000 times smaller than a proton or neutron (12000th)
bull If you could make a model of the nucleus think of a proton and neutron about the size of an apple and orange
bull At this size an electron would be about the size of a fruit fly
Size of Atom
bull Even though an atom is small it is mostly
empty space
bull If you could make a model of an atom the
size of a football field The nucleus of an
atom would be the size of an ant
Standard 3a ndash The Structure of an Atom
bullA typical single strand of human hair is
10 million carbon atoms wide
bullA single drop of water contains 2
sextillion (2x1021) atoms of oxygen and
twice as many hydrogen atoms
bullWe are able to see the surface of atoms
by using a scanning tunneling electron
microscope
Whatrsquos Inside
bull How do we know what is inside of an
atom
Mystery Bags (Pg 2 Spiral)
bull (These are directions- you donrsquot have to write
this) You will be given a paper bag that has
something unknown inside Your job is to guess
what it is WITHOUT looking in the bag (The
bag stays closed at all times)
bull You can touch it smell it listen to it etc Is it
hard Soft Shape Thickness Write down all
of your observations
bull Then guess what it might be
Standard 3a ndash The Structure of an
Atom
Question How do we know what atoms are
made of if we can only see the outside
Atomic Model
Answer Over many
years scientists
have developed a
model based on
indirect experiments
on matter
History of the Atom (pg 3 spiral)
bull Who was responsible for our path of
understanding the atom
bull We are still learning about the atom today
Dalton 1766-1844
bull He thought an atom was a simple neutral
sphere of indivisible matter that was the
same throughout
bull Atoms of different elements were different
from one another (gold vs iron)
bull All gold was made from gold atoms and all
iron was made from iron atoms etc
bull Pg 178TB Daltonrsquos atomic symbols
Thomson 1897
bull In the 1800rsquos JJ Thomson discovered electronsbull httphigheredmcgraw-
hillcomolcwebcgipluginpopcgiit=swf100100sitesdlfree007251264411735401_Cathode_Ray_TubeswfCathode20Ray20Tube
bull He was able to bend the light of a cathode ray with magnets The ray bent towards the positive plate so he knew that there was a negative charge (He called that negative charge an electron)
bull There must be a positive charge to balance this because atoms are neutral
bull Chocolate chip cookie model (Positive dough with negative chocolate chips throughout)
bull He concluded that atoms can be divided
Rutherford 1911
bull Discovered the nucleus (positive charge) Protons
bull Gold foil experimentbull httpwwwmhhecomphysscichemistryessentialchemistryflashruther14swf
bull Positively charged Alpha particles were shot at a
really thin piece of gold foil
bull Some particles went through the foil some went
off to the sides and a few bounced back
bull He compared the ones that bounced back as
amazing as if a cannon ball bouncing off of a
kleenex (approx 1 in 8000)
Chadwick 1932
bull Discovered neutrons
bull Working with the cathode ray they (Rutherford
and his students) looked for protons (+1 charge)
and knew the approximate mass of elements
bull They could not account for all of the mass so he
predicted that there was a neutral particle in the
nucleus with the proton and named it a neutron
bull neutron- neutral-no charge
Bohr
bull Electrons are arranged in energy levels
bull The closer energy levels hold just a few and the outer levels hold more
bull Just like a person stands on a ladder and has to move to the next step (rung) an electron can only jump to the next energy level
bull He discovered this working with spectral lines in a single wavelength of light
Todayrsquos Model
bull Electrons occupy a space around the
nucleus in the electron cloud
bull They do not orbit like planets around the
sun but move rapidly from one place to
another
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
Size of Atom
bull Even though an atom is small it is mostly
empty space
bull If you could make a model of an atom the
size of a football field The nucleus of an
atom would be the size of an ant
Standard 3a ndash The Structure of an Atom
bullA typical single strand of human hair is
10 million carbon atoms wide
bullA single drop of water contains 2
sextillion (2x1021) atoms of oxygen and
twice as many hydrogen atoms
bullWe are able to see the surface of atoms
by using a scanning tunneling electron
microscope
Whatrsquos Inside
bull How do we know what is inside of an
atom
Mystery Bags (Pg 2 Spiral)
bull (These are directions- you donrsquot have to write
this) You will be given a paper bag that has
something unknown inside Your job is to guess
what it is WITHOUT looking in the bag (The
bag stays closed at all times)
bull You can touch it smell it listen to it etc Is it
hard Soft Shape Thickness Write down all
of your observations
bull Then guess what it might be
Standard 3a ndash The Structure of an
Atom
Question How do we know what atoms are
made of if we can only see the outside
Atomic Model
Answer Over many
years scientists
have developed a
model based on
indirect experiments
on matter
History of the Atom (pg 3 spiral)
bull Who was responsible for our path of
understanding the atom
bull We are still learning about the atom today
Dalton 1766-1844
bull He thought an atom was a simple neutral
sphere of indivisible matter that was the
same throughout
bull Atoms of different elements were different
from one another (gold vs iron)
bull All gold was made from gold atoms and all
iron was made from iron atoms etc
bull Pg 178TB Daltonrsquos atomic symbols
Thomson 1897
bull In the 1800rsquos JJ Thomson discovered electronsbull httphigheredmcgraw-
hillcomolcwebcgipluginpopcgiit=swf100100sitesdlfree007251264411735401_Cathode_Ray_TubeswfCathode20Ray20Tube
bull He was able to bend the light of a cathode ray with magnets The ray bent towards the positive plate so he knew that there was a negative charge (He called that negative charge an electron)
bull There must be a positive charge to balance this because atoms are neutral
bull Chocolate chip cookie model (Positive dough with negative chocolate chips throughout)
bull He concluded that atoms can be divided
Rutherford 1911
bull Discovered the nucleus (positive charge) Protons
bull Gold foil experimentbull httpwwwmhhecomphysscichemistryessentialchemistryflashruther14swf
bull Positively charged Alpha particles were shot at a
really thin piece of gold foil
bull Some particles went through the foil some went
off to the sides and a few bounced back
bull He compared the ones that bounced back as
amazing as if a cannon ball bouncing off of a
kleenex (approx 1 in 8000)
Chadwick 1932
bull Discovered neutrons
bull Working with the cathode ray they (Rutherford
and his students) looked for protons (+1 charge)
and knew the approximate mass of elements
bull They could not account for all of the mass so he
predicted that there was a neutral particle in the
nucleus with the proton and named it a neutron
bull neutron- neutral-no charge
Bohr
bull Electrons are arranged in energy levels
bull The closer energy levels hold just a few and the outer levels hold more
bull Just like a person stands on a ladder and has to move to the next step (rung) an electron can only jump to the next energy level
bull He discovered this working with spectral lines in a single wavelength of light
Todayrsquos Model
bull Electrons occupy a space around the
nucleus in the electron cloud
bull They do not orbit like planets around the
sun but move rapidly from one place to
another
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
Standard 3a ndash The Structure of an Atom
bullA typical single strand of human hair is
10 million carbon atoms wide
bullA single drop of water contains 2
sextillion (2x1021) atoms of oxygen and
twice as many hydrogen atoms
bullWe are able to see the surface of atoms
by using a scanning tunneling electron
microscope
Whatrsquos Inside
bull How do we know what is inside of an
atom
Mystery Bags (Pg 2 Spiral)
bull (These are directions- you donrsquot have to write
this) You will be given a paper bag that has
something unknown inside Your job is to guess
what it is WITHOUT looking in the bag (The
bag stays closed at all times)
bull You can touch it smell it listen to it etc Is it
hard Soft Shape Thickness Write down all
of your observations
bull Then guess what it might be
Standard 3a ndash The Structure of an
Atom
Question How do we know what atoms are
made of if we can only see the outside
Atomic Model
Answer Over many
years scientists
have developed a
model based on
indirect experiments
on matter
History of the Atom (pg 3 spiral)
bull Who was responsible for our path of
understanding the atom
bull We are still learning about the atom today
Dalton 1766-1844
bull He thought an atom was a simple neutral
sphere of indivisible matter that was the
same throughout
bull Atoms of different elements were different
from one another (gold vs iron)
bull All gold was made from gold atoms and all
iron was made from iron atoms etc
bull Pg 178TB Daltonrsquos atomic symbols
Thomson 1897
bull In the 1800rsquos JJ Thomson discovered electronsbull httphigheredmcgraw-
hillcomolcwebcgipluginpopcgiit=swf100100sitesdlfree007251264411735401_Cathode_Ray_TubeswfCathode20Ray20Tube
bull He was able to bend the light of a cathode ray with magnets The ray bent towards the positive plate so he knew that there was a negative charge (He called that negative charge an electron)
bull There must be a positive charge to balance this because atoms are neutral
bull Chocolate chip cookie model (Positive dough with negative chocolate chips throughout)
bull He concluded that atoms can be divided
Rutherford 1911
bull Discovered the nucleus (positive charge) Protons
bull Gold foil experimentbull httpwwwmhhecomphysscichemistryessentialchemistryflashruther14swf
bull Positively charged Alpha particles were shot at a
really thin piece of gold foil
bull Some particles went through the foil some went
off to the sides and a few bounced back
bull He compared the ones that bounced back as
amazing as if a cannon ball bouncing off of a
kleenex (approx 1 in 8000)
Chadwick 1932
bull Discovered neutrons
bull Working with the cathode ray they (Rutherford
and his students) looked for protons (+1 charge)
and knew the approximate mass of elements
bull They could not account for all of the mass so he
predicted that there was a neutral particle in the
nucleus with the proton and named it a neutron
bull neutron- neutral-no charge
Bohr
bull Electrons are arranged in energy levels
bull The closer energy levels hold just a few and the outer levels hold more
bull Just like a person stands on a ladder and has to move to the next step (rung) an electron can only jump to the next energy level
bull He discovered this working with spectral lines in a single wavelength of light
Todayrsquos Model
bull Electrons occupy a space around the
nucleus in the electron cloud
bull They do not orbit like planets around the
sun but move rapidly from one place to
another
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
Whatrsquos Inside
bull How do we know what is inside of an
atom
Mystery Bags (Pg 2 Spiral)
bull (These are directions- you donrsquot have to write
this) You will be given a paper bag that has
something unknown inside Your job is to guess
what it is WITHOUT looking in the bag (The
bag stays closed at all times)
bull You can touch it smell it listen to it etc Is it
hard Soft Shape Thickness Write down all
of your observations
bull Then guess what it might be
Standard 3a ndash The Structure of an
Atom
Question How do we know what atoms are
made of if we can only see the outside
Atomic Model
Answer Over many
years scientists
have developed a
model based on
indirect experiments
on matter
History of the Atom (pg 3 spiral)
bull Who was responsible for our path of
understanding the atom
bull We are still learning about the atom today
Dalton 1766-1844
bull He thought an atom was a simple neutral
sphere of indivisible matter that was the
same throughout
bull Atoms of different elements were different
from one another (gold vs iron)
bull All gold was made from gold atoms and all
iron was made from iron atoms etc
bull Pg 178TB Daltonrsquos atomic symbols
Thomson 1897
bull In the 1800rsquos JJ Thomson discovered electronsbull httphigheredmcgraw-
hillcomolcwebcgipluginpopcgiit=swf100100sitesdlfree007251264411735401_Cathode_Ray_TubeswfCathode20Ray20Tube
bull He was able to bend the light of a cathode ray with magnets The ray bent towards the positive plate so he knew that there was a negative charge (He called that negative charge an electron)
bull There must be a positive charge to balance this because atoms are neutral
bull Chocolate chip cookie model (Positive dough with negative chocolate chips throughout)
bull He concluded that atoms can be divided
Rutherford 1911
bull Discovered the nucleus (positive charge) Protons
bull Gold foil experimentbull httpwwwmhhecomphysscichemistryessentialchemistryflashruther14swf
bull Positively charged Alpha particles were shot at a
really thin piece of gold foil
bull Some particles went through the foil some went
off to the sides and a few bounced back
bull He compared the ones that bounced back as
amazing as if a cannon ball bouncing off of a
kleenex (approx 1 in 8000)
Chadwick 1932
bull Discovered neutrons
bull Working with the cathode ray they (Rutherford
and his students) looked for protons (+1 charge)
and knew the approximate mass of elements
bull They could not account for all of the mass so he
predicted that there was a neutral particle in the
nucleus with the proton and named it a neutron
bull neutron- neutral-no charge
Bohr
bull Electrons are arranged in energy levels
bull The closer energy levels hold just a few and the outer levels hold more
bull Just like a person stands on a ladder and has to move to the next step (rung) an electron can only jump to the next energy level
bull He discovered this working with spectral lines in a single wavelength of light
Todayrsquos Model
bull Electrons occupy a space around the
nucleus in the electron cloud
bull They do not orbit like planets around the
sun but move rapidly from one place to
another
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
Mystery Bags (Pg 2 Spiral)
bull (These are directions- you donrsquot have to write
this) You will be given a paper bag that has
something unknown inside Your job is to guess
what it is WITHOUT looking in the bag (The
bag stays closed at all times)
bull You can touch it smell it listen to it etc Is it
hard Soft Shape Thickness Write down all
of your observations
bull Then guess what it might be
Standard 3a ndash The Structure of an
Atom
Question How do we know what atoms are
made of if we can only see the outside
Atomic Model
Answer Over many
years scientists
have developed a
model based on
indirect experiments
on matter
History of the Atom (pg 3 spiral)
bull Who was responsible for our path of
understanding the atom
bull We are still learning about the atom today
Dalton 1766-1844
bull He thought an atom was a simple neutral
sphere of indivisible matter that was the
same throughout
bull Atoms of different elements were different
from one another (gold vs iron)
bull All gold was made from gold atoms and all
iron was made from iron atoms etc
bull Pg 178TB Daltonrsquos atomic symbols
Thomson 1897
bull In the 1800rsquos JJ Thomson discovered electronsbull httphigheredmcgraw-
hillcomolcwebcgipluginpopcgiit=swf100100sitesdlfree007251264411735401_Cathode_Ray_TubeswfCathode20Ray20Tube
bull He was able to bend the light of a cathode ray with magnets The ray bent towards the positive plate so he knew that there was a negative charge (He called that negative charge an electron)
bull There must be a positive charge to balance this because atoms are neutral
bull Chocolate chip cookie model (Positive dough with negative chocolate chips throughout)
bull He concluded that atoms can be divided
Rutherford 1911
bull Discovered the nucleus (positive charge) Protons
bull Gold foil experimentbull httpwwwmhhecomphysscichemistryessentialchemistryflashruther14swf
bull Positively charged Alpha particles were shot at a
really thin piece of gold foil
bull Some particles went through the foil some went
off to the sides and a few bounced back
bull He compared the ones that bounced back as
amazing as if a cannon ball bouncing off of a
kleenex (approx 1 in 8000)
Chadwick 1932
bull Discovered neutrons
bull Working with the cathode ray they (Rutherford
and his students) looked for protons (+1 charge)
and knew the approximate mass of elements
bull They could not account for all of the mass so he
predicted that there was a neutral particle in the
nucleus with the proton and named it a neutron
bull neutron- neutral-no charge
Bohr
bull Electrons are arranged in energy levels
bull The closer energy levels hold just a few and the outer levels hold more
bull Just like a person stands on a ladder and has to move to the next step (rung) an electron can only jump to the next energy level
bull He discovered this working with spectral lines in a single wavelength of light
Todayrsquos Model
bull Electrons occupy a space around the
nucleus in the electron cloud
bull They do not orbit like planets around the
sun but move rapidly from one place to
another
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
Standard 3a ndash The Structure of an
Atom
Question How do we know what atoms are
made of if we can only see the outside
Atomic Model
Answer Over many
years scientists
have developed a
model based on
indirect experiments
on matter
History of the Atom (pg 3 spiral)
bull Who was responsible for our path of
understanding the atom
bull We are still learning about the atom today
Dalton 1766-1844
bull He thought an atom was a simple neutral
sphere of indivisible matter that was the
same throughout
bull Atoms of different elements were different
from one another (gold vs iron)
bull All gold was made from gold atoms and all
iron was made from iron atoms etc
bull Pg 178TB Daltonrsquos atomic symbols
Thomson 1897
bull In the 1800rsquos JJ Thomson discovered electronsbull httphigheredmcgraw-
hillcomolcwebcgipluginpopcgiit=swf100100sitesdlfree007251264411735401_Cathode_Ray_TubeswfCathode20Ray20Tube
bull He was able to bend the light of a cathode ray with magnets The ray bent towards the positive plate so he knew that there was a negative charge (He called that negative charge an electron)
bull There must be a positive charge to balance this because atoms are neutral
bull Chocolate chip cookie model (Positive dough with negative chocolate chips throughout)
bull He concluded that atoms can be divided
Rutherford 1911
bull Discovered the nucleus (positive charge) Protons
bull Gold foil experimentbull httpwwwmhhecomphysscichemistryessentialchemistryflashruther14swf
bull Positively charged Alpha particles were shot at a
really thin piece of gold foil
bull Some particles went through the foil some went
off to the sides and a few bounced back
bull He compared the ones that bounced back as
amazing as if a cannon ball bouncing off of a
kleenex (approx 1 in 8000)
Chadwick 1932
bull Discovered neutrons
bull Working with the cathode ray they (Rutherford
and his students) looked for protons (+1 charge)
and knew the approximate mass of elements
bull They could not account for all of the mass so he
predicted that there was a neutral particle in the
nucleus with the proton and named it a neutron
bull neutron- neutral-no charge
Bohr
bull Electrons are arranged in energy levels
bull The closer energy levels hold just a few and the outer levels hold more
bull Just like a person stands on a ladder and has to move to the next step (rung) an electron can only jump to the next energy level
bull He discovered this working with spectral lines in a single wavelength of light
Todayrsquos Model
bull Electrons occupy a space around the
nucleus in the electron cloud
bull They do not orbit like planets around the
sun but move rapidly from one place to
another
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
History of the Atom (pg 3 spiral)
bull Who was responsible for our path of
understanding the atom
bull We are still learning about the atom today
Dalton 1766-1844
bull He thought an atom was a simple neutral
sphere of indivisible matter that was the
same throughout
bull Atoms of different elements were different
from one another (gold vs iron)
bull All gold was made from gold atoms and all
iron was made from iron atoms etc
bull Pg 178TB Daltonrsquos atomic symbols
Thomson 1897
bull In the 1800rsquos JJ Thomson discovered electronsbull httphigheredmcgraw-
hillcomolcwebcgipluginpopcgiit=swf100100sitesdlfree007251264411735401_Cathode_Ray_TubeswfCathode20Ray20Tube
bull He was able to bend the light of a cathode ray with magnets The ray bent towards the positive plate so he knew that there was a negative charge (He called that negative charge an electron)
bull There must be a positive charge to balance this because atoms are neutral
bull Chocolate chip cookie model (Positive dough with negative chocolate chips throughout)
bull He concluded that atoms can be divided
Rutherford 1911
bull Discovered the nucleus (positive charge) Protons
bull Gold foil experimentbull httpwwwmhhecomphysscichemistryessentialchemistryflashruther14swf
bull Positively charged Alpha particles were shot at a
really thin piece of gold foil
bull Some particles went through the foil some went
off to the sides and a few bounced back
bull He compared the ones that bounced back as
amazing as if a cannon ball bouncing off of a
kleenex (approx 1 in 8000)
Chadwick 1932
bull Discovered neutrons
bull Working with the cathode ray they (Rutherford
and his students) looked for protons (+1 charge)
and knew the approximate mass of elements
bull They could not account for all of the mass so he
predicted that there was a neutral particle in the
nucleus with the proton and named it a neutron
bull neutron- neutral-no charge
Bohr
bull Electrons are arranged in energy levels
bull The closer energy levels hold just a few and the outer levels hold more
bull Just like a person stands on a ladder and has to move to the next step (rung) an electron can only jump to the next energy level
bull He discovered this working with spectral lines in a single wavelength of light
Todayrsquos Model
bull Electrons occupy a space around the
nucleus in the electron cloud
bull They do not orbit like planets around the
sun but move rapidly from one place to
another
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
Dalton 1766-1844
bull He thought an atom was a simple neutral
sphere of indivisible matter that was the
same throughout
bull Atoms of different elements were different
from one another (gold vs iron)
bull All gold was made from gold atoms and all
iron was made from iron atoms etc
bull Pg 178TB Daltonrsquos atomic symbols
Thomson 1897
bull In the 1800rsquos JJ Thomson discovered electronsbull httphigheredmcgraw-
hillcomolcwebcgipluginpopcgiit=swf100100sitesdlfree007251264411735401_Cathode_Ray_TubeswfCathode20Ray20Tube
bull He was able to bend the light of a cathode ray with magnets The ray bent towards the positive plate so he knew that there was a negative charge (He called that negative charge an electron)
bull There must be a positive charge to balance this because atoms are neutral
bull Chocolate chip cookie model (Positive dough with negative chocolate chips throughout)
bull He concluded that atoms can be divided
Rutherford 1911
bull Discovered the nucleus (positive charge) Protons
bull Gold foil experimentbull httpwwwmhhecomphysscichemistryessentialchemistryflashruther14swf
bull Positively charged Alpha particles were shot at a
really thin piece of gold foil
bull Some particles went through the foil some went
off to the sides and a few bounced back
bull He compared the ones that bounced back as
amazing as if a cannon ball bouncing off of a
kleenex (approx 1 in 8000)
Chadwick 1932
bull Discovered neutrons
bull Working with the cathode ray they (Rutherford
and his students) looked for protons (+1 charge)
and knew the approximate mass of elements
bull They could not account for all of the mass so he
predicted that there was a neutral particle in the
nucleus with the proton and named it a neutron
bull neutron- neutral-no charge
Bohr
bull Electrons are arranged in energy levels
bull The closer energy levels hold just a few and the outer levels hold more
bull Just like a person stands on a ladder and has to move to the next step (rung) an electron can only jump to the next energy level
bull He discovered this working with spectral lines in a single wavelength of light
Todayrsquos Model
bull Electrons occupy a space around the
nucleus in the electron cloud
bull They do not orbit like planets around the
sun but move rapidly from one place to
another
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
Thomson 1897
bull In the 1800rsquos JJ Thomson discovered electronsbull httphigheredmcgraw-
hillcomolcwebcgipluginpopcgiit=swf100100sitesdlfree007251264411735401_Cathode_Ray_TubeswfCathode20Ray20Tube
bull He was able to bend the light of a cathode ray with magnets The ray bent towards the positive plate so he knew that there was a negative charge (He called that negative charge an electron)
bull There must be a positive charge to balance this because atoms are neutral
bull Chocolate chip cookie model (Positive dough with negative chocolate chips throughout)
bull He concluded that atoms can be divided
Rutherford 1911
bull Discovered the nucleus (positive charge) Protons
bull Gold foil experimentbull httpwwwmhhecomphysscichemistryessentialchemistryflashruther14swf
bull Positively charged Alpha particles were shot at a
really thin piece of gold foil
bull Some particles went through the foil some went
off to the sides and a few bounced back
bull He compared the ones that bounced back as
amazing as if a cannon ball bouncing off of a
kleenex (approx 1 in 8000)
Chadwick 1932
bull Discovered neutrons
bull Working with the cathode ray they (Rutherford
and his students) looked for protons (+1 charge)
and knew the approximate mass of elements
bull They could not account for all of the mass so he
predicted that there was a neutral particle in the
nucleus with the proton and named it a neutron
bull neutron- neutral-no charge
Bohr
bull Electrons are arranged in energy levels
bull The closer energy levels hold just a few and the outer levels hold more
bull Just like a person stands on a ladder and has to move to the next step (rung) an electron can only jump to the next energy level
bull He discovered this working with spectral lines in a single wavelength of light
Todayrsquos Model
bull Electrons occupy a space around the
nucleus in the electron cloud
bull They do not orbit like planets around the
sun but move rapidly from one place to
another
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
Rutherford 1911
bull Discovered the nucleus (positive charge) Protons
bull Gold foil experimentbull httpwwwmhhecomphysscichemistryessentialchemistryflashruther14swf
bull Positively charged Alpha particles were shot at a
really thin piece of gold foil
bull Some particles went through the foil some went
off to the sides and a few bounced back
bull He compared the ones that bounced back as
amazing as if a cannon ball bouncing off of a
kleenex (approx 1 in 8000)
Chadwick 1932
bull Discovered neutrons
bull Working with the cathode ray they (Rutherford
and his students) looked for protons (+1 charge)
and knew the approximate mass of elements
bull They could not account for all of the mass so he
predicted that there was a neutral particle in the
nucleus with the proton and named it a neutron
bull neutron- neutral-no charge
Bohr
bull Electrons are arranged in energy levels
bull The closer energy levels hold just a few and the outer levels hold more
bull Just like a person stands on a ladder and has to move to the next step (rung) an electron can only jump to the next energy level
bull He discovered this working with spectral lines in a single wavelength of light
Todayrsquos Model
bull Electrons occupy a space around the
nucleus in the electron cloud
bull They do not orbit like planets around the
sun but move rapidly from one place to
another
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
Chadwick 1932
bull Discovered neutrons
bull Working with the cathode ray they (Rutherford
and his students) looked for protons (+1 charge)
and knew the approximate mass of elements
bull They could not account for all of the mass so he
predicted that there was a neutral particle in the
nucleus with the proton and named it a neutron
bull neutron- neutral-no charge
Bohr
bull Electrons are arranged in energy levels
bull The closer energy levels hold just a few and the outer levels hold more
bull Just like a person stands on a ladder and has to move to the next step (rung) an electron can only jump to the next energy level
bull He discovered this working with spectral lines in a single wavelength of light
Todayrsquos Model
bull Electrons occupy a space around the
nucleus in the electron cloud
bull They do not orbit like planets around the
sun but move rapidly from one place to
another
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
Bohr
bull Electrons are arranged in energy levels
bull The closer energy levels hold just a few and the outer levels hold more
bull Just like a person stands on a ladder and has to move to the next step (rung) an electron can only jump to the next energy level
bull He discovered this working with spectral lines in a single wavelength of light
Todayrsquos Model
bull Electrons occupy a space around the
nucleus in the electron cloud
bull They do not orbit like planets around the
sun but move rapidly from one place to
another
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
Todayrsquos Model
bull Electrons occupy a space around the
nucleus in the electron cloud
bull They do not orbit like planets around the
sun but move rapidly from one place to
another
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
Whorsquos Model
bull 1
bull 1 Thomson
bull 2
bull 2 Bohr
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
Whorsquos Model
bull 3
bull 3 Dalton
bull 4
bull 4 Rutherford
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
Whorsquos Model
bull 5
bull 5 Todayrsquos model
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
Standard 3a ndash The Structure of an Atom
protons
electrons
nucleus
neutrons
The electron cloud
About 1 amu
About 0 amu
About 1 amu
Electron cloud
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
QUIZ TIME
bull Quiz on clickers
bull Write your answers on Page 4 in your
spiral
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