Atomic Structure 3.1
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Atomic StructureAtomic Structure
3.1
October 1, 2015October 1, 2015
Objective: Explain Dalton’s atomic theory and describe why it was more successful than Democritus’ atomic theory.
Do Now: Name the 3 subatomic particles found in an atom (the 3 parts of an atom).
Objective: Explain Dalton’s atomic theory and describe why it was more successful than Democritus’ atomic theory.
Do Now: Name the 3 subatomic particles found in an atom (the 3 parts of an atom).
Atomic HistoryAtomic History
•In 400 BC a Greek Philosopher, Democritus suggested the universe was made of invisible units--atoms.
•In 400 BC a Greek Philosopher, Democritus suggested the universe was made of invisible units--atoms.
1800’s John Dalton’s Theory
(Still Accepted)
1800’s John Dalton’s Theory
(Still Accepted)
1.Every element is made of tiny, unique particles called atoms
2.Atoms of different elements can join to form molecules.
1.Every element is made of tiny, unique particles called atoms
2.Atoms of different elements can join to form molecules.
John Dalton’s Theory- DisprovedJohn Dalton’s Theory- Disproved
3.Atoms are the smallest particles and cannot be subdivided.
4.Atoms of the same element are exactly alike in mass
3.Atoms are the smallest particles and cannot be subdivided.
4.Atoms of the same element are exactly alike in mass
JJ ThomsonJJ Thomson
Credited with discovering negative charged particles called electrons.
Credited with discovering negative charged particles called electrons.
https://www.youtube.com/watch?v=2xKZRpAsWL8
https://www.youtube.com/watch?v=O9Goyscbazk
RutherfordRutherford
Credited with discovering nucleus.
and atoms are mostly empty space.
Credited with discovering nucleus.
and atoms are mostly empty space.
https://www.youtube.com/watch?v=5pZj0u_XMbc
http://micro.magnet.fsu.edu/electromag/java/rutherford/
Further Research FindingFurther Research Finding
Later on, the discovery of protons and neutrons were discovered in the nucleus.
And it was later concluded that all atoms are neutral in charge.
The number of protons and electrons in any atom are always equal.
Later on, the discovery of protons and neutrons were discovered in the nucleus.
And it was later concluded that all atoms are neutral in charge.
The number of protons and electrons in any atom are always equal.
Niels BohrNiels BohrSuggested that electrons move around atoms in set paths around the nucleus.
He said each path is an energy level
Suggested that electrons move around atoms in set paths around the nucleus.
He said each path is an energy level
See visual aid in Ch4 online txtbk
Today’s TheoryToday’s Theory
It is impossible to pinpoint an electron’s exact position due to its tremendous speed.
Electrons do not move around in definite paths.
It is impossible to pinpoint an electron’s exact position due to its tremendous speed.
Electrons do not move around in definite paths.
Today’s TheoryToday’s Theory
Electrons are found in orbitals within energy levels. (s, p, d, and f )a region in an atom where there is a high probability of finding electrons.
Electrons are found in orbitals within energy levels. (s, p, d, and f )a region in an atom where there is a high probability of finding electrons.
Today’s TheoryToday’s TheoryElectrons are now viewed as waves vibrating on a string rather than simple particles.
Wave-Particle Duality Theory
Electrons are now viewed as waves vibrating on a string rather than simple particles.
Wave-Particle Duality Theory
What are atoms?What are atoms?
The smallest part of an element that still has the element’s properties.
The smallest part of an element that still has the element’s properties.
Parts of an atomParts of an atom
NucleusProtonNeutron
Electron
NucleusProtonNeutron
Electron
Subatomic particles
NucleusNucleus•center of an atom
•positively charged
•makes up 99.9% of the atom’s mass
•contains protons and neutrons
•center of an atom
•positively charged
•makes up 99.9% of the atom’s mass
•contains protons and neutrons
ProtonsProtonsCharge (+)
Mass is equal to 1 atomic mass unit (amu)
Found in the nucleus
Identifies the element/atom
Charge (+)
Mass is equal to 1 atomic mass unit (amu)
Found in the nucleus
Identifies the element/atom
NeutronsNeutronsCharge (0) – neutral
Mass is equal to 1amu
Found in the nucleus
Helps determine mass
Charge (0) – neutral
Mass is equal to 1amu
Found in the nucleus
Helps determine mass
ElectronsElectrons•Charge is negative (-)
•Mass is equal to 0 amu
•Found outside the nucleus, in the electron cloud
•Charge is negative (-)
•Mass is equal to 0 amu
•Found outside the nucleus, in the electron cloud
Energy levels Energy levels
1st level holds up to 2 e- 2nd level holds up to 8 e- 3rd level holds up to 8 or 18 e-
4th level holds up to 8, 18, or 32 e-
Outer Level holds up to 8 e-(called valence electrons)
1st level holds up to 2 e- 2nd level holds up to 8 e- 3rd level holds up to 8 or 18 e-
4th level holds up to 8, 18, or 32 e-
Outer Level holds up to 8 e-(called valence electrons)
Valence ElectronValence Electron
The number of electrons in the outermost electron shell.
Most important
The number of electrons in the outermost electron shell.
Most important
Oct 6, 2014Oct 6, 2014
Objective: Quantify atoms and ions based on subatomic particles
Do Now: How many valence e- will the following elements have? (Draw out your energy orbitals with the “nucleus” in the center to show work) Carbon
Na
Hydrogen
Chlorine
Objective: Quantify atoms and ions based on subatomic particles
Do Now: How many valence e- will the following elements have? (Draw out your energy orbitals with the “nucleus” in the center to show work) Carbon
Na
Hydrogen
Chlorine
A Guided Tour of the Periodic Table
A Guided Tour of the Periodic Table
3.23.2 https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=meet%20the%20elements Meet the Elements
Periodic Law Periodic Law
•Properties of elements tend to change in a regular pattern when elements are arranged in order of increasing atomic number.
•Properties of elements tend to change in a regular pattern when elements are arranged in order of increasing atomic number.
Periodic Law Periodic Law
Periodic Table is set up by increasing atomic number.
Atomic Number is the # of protons in the atom.
Periodic Table is set up by increasing atomic number.
Atomic Number is the # of protons in the atom.
Average Atomic
Mass
Atomic Number Atomic Number•tells you number of protons•Never Changes for an atom.•Appears as a whole # on the periodic table.•No two elements can have same atomic #.
•tells you number of protons•Never Changes for an atom.•Appears as a whole # on the periodic table.•No two elements can have same atomic #.
Atomic NumberAtomic Number
# of protons
Atomic Number
Mass Number Mass Number
The mass of an atomTotal number of protons plus
neutrons in the nucleus of a single atom.
Atoms of the same element won’t always have the same mass number
The mass of an atomTotal number of protons plus
neutrons in the nucleus of a single atom.
Atoms of the same element won’t always have the same mass number
Mass NumberMass Number
# of protons
# ofneutrons Mass
#
Isotopes Isotopes
•Any atoms having the same number of protons but different number of neutrons.•So they also have different mass numbers.
•Any atoms having the same number of protons but different number of neutrons.•So they also have different mass numbers.
Average Atomic MassAverage Atomic Mass
Average mass of all known isotopes for an element
Found on the periodic table as a number with a decimal
Average mass of all known isotopes for an element
Found on the periodic table as a number with a decimal
Atom’s Charge Atom’s Charge
•They are neutral.
•All atoms have the same number of protons and electrons.
•Charges cancel each other out.
•They are neutral.
•All atoms have the same number of protons and electrons.
•Charges cancel each other out.
Ions Ions
Charged particles. Form when atoms lose or gain
electrons.They do this so the ions have a
full outer shellTwo Types.
Charged particles. Form when atoms lose or gain
electrons.They do this so the ions have a
full outer shellTwo Types.
Cations Cations
•Positively charged ions.
•Form when atoms lose electrons.
•Metals
•Left side of table
•Positively charged ions.
•Form when atoms lose electrons.
•Metals
•Left side of table
Cations Cations
# of protons greater than # of electrons
More (+) than (-)
# of protons greater than # of electrons
More (+) than (-)
Na AtomNa+ Cation
Anions Anions
•Negatively charged ions. •Form when atoms gain electrons.•Nonmetals•Right side of table
•Negatively charged ions. •Form when atoms gain electrons.•Nonmetals•Right side of table
Anions Anions
# of protons less than # of electrons
More (-) than (+)
# of protons less than # of electrons
More (-) than (+)
Cl atom
Cl- Anion
Quantifying atoms or ionsQuantifying atoms or ions
+1 Protons = 3
Neutrons = 7-3 = 4
Electrons = 3
Electrons = 3 -1 = 2
Families of Elements
Families of Elements
3.33.3
Periodic TablePeriodic TablePeriods
-a horizontal row of elements.
-Tells you the electrons energy level.
Periods
-a horizontal row of elements.
-Tells you the electrons energy level.
Periodic TablePeriodic TableGroups (families) -a vertical column of elements.
-Tells us the # of valence electrons and the elements’ chemical properties.
Groups (families) -a vertical column of elements.
-Tells us the # of valence electrons and the elements’ chemical properties.
Types of ElementsTypes of Elements
1.Metals
2.Nonmetals
3.Semiconductors/metalloid
1.Metals
2.Nonmetals
3.Semiconductors/metalloid
Transition Metals
Alkaline Earth Metals
Alkali Metals
Metalloids
Other Metals
Non Metals
Halogens
Nobel Gases
Inner Transition Metals
Alkali Metals Group 1Alkali Metals Group 1Most reactive metals one valence e-Found as compounds (salts) and not
elements due to reactivity.As elements they are soft metals and
good conductors.
Most reactive metals one valence e-Found as compounds (salts) and not
elements due to reactivity.As elements they are soft metals and
good conductors.
fun
Alkaline-earth MetalsGroup 2
Alkaline-earth MetalsGroup 2
Less reactive than AlkaliThey are also more commonly found as compounds
2 most common are Ca and Mg.
Less reactive than AlkaliThey are also more commonly found as compounds
2 most common are Ca and Mg.
Transition Metals Groups 3-12
Transition Metals Groups 3-12
Less reactive than groups 1 and 2
Good conductors
Less reactive than groups 1 and 2
Good conductors
Transition MetalsTransition Metals
All solids with the exception of mercury
Valuable metals (Ag, Au, Pt, Cu, Ni, Fe, Co)
All solids with the exception of mercury
Valuable metals (Ag, Au, Pt, Cu, Ni, Fe, Co)
Non MetalsNon Metals
Are not able to conduct electricity or heat very well.
Found in groups 13-18, with the exception of hydrogen
Are not able to conduct electricity or heat very well.
Found in groups 13-18, with the exception of hydrogen
CarbonCarbon
Found as an element (coal, diamond, graphite)
Found in millions of different compounds
Called Organic Compounds
Found as an element (coal, diamond, graphite)
Found in millions of different compounds
Called Organic Compounds
HYDROGENHYDROGENIt is a gas/nonmetalA very explosive gas.It is located in group one
because it has one valence electron
http://www.youtube.com/watch?v=KLzY88uHFn0
It is a gas/nonmetalA very explosive gas.It is located in group one
because it has one valence electron
http://www.youtube.com/watch?v=KLzY88uHFn0
Oxygen and NitrogenOxygen and Nitrogen
Oxygen is the most common element found on Earth
Nitrogen most common gas found in the atmosphere
Oxygen is the most common element found on Earth
Nitrogen most common gas found in the atmosphere
Halogens Group 17
Halogens Group 17
Most reactive nonmetalsForm salts with group 1Used to kill bacteriaBromine only liquid nonmetal
Most reactive nonmetalsForm salts with group 1Used to kill bacteriaBromine only liquid nonmetal
Noble Gases Group 18Noble Gases Group 18Stable and not reactive. (inert)
Don’t form compounds.They have a full valence shell.
Stable and not reactive. (inert)
Don’t form compounds.They have a full valence shell.
Metalloids (Semiconductors)
Metalloids (Semiconductors)
7 elements on the step
Properties of both metals and non-metals.
Silicon the most familiar (computer chips)
7 elements on the step
Properties of both metals and non-metals.
Silicon the most familiar (computer chips)
Inner Transition MetalsInner Transition MetalsTwo rows at the bottomSome are Radioactive ex. Uranium
93 and greater are all manmade
Two rows at the bottomSome are Radioactive ex. Uranium
93 and greater are all manmade
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