Unit 2
Typically found above group 1A.
Has 1 valence electron.
Can form a +1 or a -1 charge.
Because of this we can consider it to be a metal
and a non-metal.
Very reactive element. Never found alone in
nature.
Group 1A
1 Valence Electron so it form ions with a +1 charge
Most reactive METALS on periodic table
Most reactive metals, not found unreacted in nature.
Li
Na
K
Rb
Cs
Fr
Li
Group 2A
2 Valence electrons so it forms a +2 charge
Harder, denser and stronger than alkali metals
Less reactive than alkali metals
Mg Not found freely in nature
Be
Mg
Ca
Sr
Ba
Sr
Ra
Ca
Group 3B – 12B
Typically form +2 charges but that can vary.
Good conductors of electricity
High luster
Typically less reactive than alkali and alkaline earth metals
Some are very unreactive and do not form compounds easily
Group 7A
7 Valence Electrons
Forms a -1 charge
Most reactive nonmetals
React vigorously with most metals to produce salts
Only group to have gas, liquids and solids.
Exist in nature as diatomic atoms : F2, Cl2, I2, Br2
Cl
F
I
Group 8A
8 Valence Electrons
Does not from a charge.
Considered unreactive
He
Ne
Ar
Kr
He
Xe
Rn
All have 2 valence electrons
Lanthanum through Yterbium
Most form +2 charges
Shiny metals similar in reactivity to alkaline earth metals
La
Ce
Pr
Nd
Pm
Sm
Eu
GD
Tb
Dy
HO
Er
Tm
Yb
Have 2 valence electrons
Most form +2 ions
All radioactive
Th through Np are found in nature
The rest are Synthetic
U
Am
U
Ac
Th
Pa
U
Np
Pu
Am
Cm
Bk
Cf
Es
Fm
Md
No