Jan 29, 2016
Vocabulary
• ATOM-An atom is the smallest unit that maintains the characteristics of an element– Nucleus- The center of the atom, contains protons
and neutrons– Electron Cloud –Region surrounding the nucleus
containing the electrons
• ELEMENT- A chemical substance that is composed of atoms with the same number of protons in the nucleus
The Atom
The Atom
NucleusProtons
Neutrons
• http://www.geocities.com/Yosemite/Rapids/1111/adamsfamsong.htm
Chorus:They are so small.(Snap, snap)They’re round like a ball.(Snap, snap)They make up the air.They’re everywhere.Can’t see them at all.(Snap, snap)
2nd Verse:Together they make gases,And liquids like molasses,And all the solid masses,The Atoms Family
Chorus:They are so small.(Snap, snap)They’re round like a ball.(Snap, snap)They make up the air.They’re everywhere.Can’t see them at all.(Snap, snap)
Chorus:They are so small.(Snap, snap)They’re round like a ball.(Snap, snap)They make up the air.They’re everywhere.Can’t see them at all.(Snap, snap)
1st Verse:They’re tiny and they’re teeny,Much smaller than a beany,They never can be seeny,The Atoms Family.
3rd Verse:Neutrons can be found,Where protons hang around;Electrons they surroundThe Atoms Family.
The NucleusProton-A positively charged sub-atomic particle
(+). Atomic Mass=1 amuThe number of protons is the same as the
atomic number
Li3
7 The atomic massThe atomic mass
The Atomic Symbol
The Nucleus
Neutrons –A sub-atomic particle in the nucleus--Has a mass equal to 1 atomic mass unit
--Neutron do not have a charge (0)To calculate the number of neutrons in an element…
Li3
7
The atomic number
The atomic massThe atomic mass
The atomic mass-The atomic number The number of neutrons
The Atom
The Electron Cloud
• Electrons-• The number of electrons equals the number of protons• Sub-atomic particle with a negative charge (-)• Mass of an electron is negligible• Electrons behave as if in a 3-D orbit
• Valence Electrons– The outer most electrons– Valence electrons are responsible for bonding
Bohr Model• The first shell can have
2 electrons• The second shell can
have 8 electrons
Shells and the Electron Cloud
Periodic Table
• Groups- Arranged by the number of valence electrons
Each group has similar bonding properties• Periods-Arranged by increasing atomic weight
Periods have the same number of shells
Example: Group 1…1 valence electronGroup 2…2 valence electronsGroup 3…3 valence electrons
Example: Period 1…1 valence shellPeriod 2…2 valence shellsPeriod 3…3 valence shells
Periodic Table
Periods go across on the periodic table
Periods have the same number of “shells”
1234567
Periodic TableGroups go down on the periodic table
Elements in the same group, have the same number of valence electrons
1 23 4 5 6 87
Let’s look at a few elements…
Hydrogen 1= Proton 1= electron
Let’s look at a few elements…
Helium 2=protons 2=neutrons2=electrons
Let’s look at a few elements…
Lithium 3=protons 4=neutrons3=electrons
Let’s look at a few elements…
Fluorine9=protons 10=neutrons
9=electrons
Let’s look at a few elements…
Argon18=protons 22=neutrons
18=electrons