How do valence electrons affect ionic bonding?

1 Answer
Apr 22, 2014

Lets take the ionic formula for Calcium Chloride is CaCl_2CaCl2

Calcium is an Alkaline Earth Metal in the second column of the periodic table. This means that calcium s^2s2 has 2 valence electrons it readily gives away in order to seek the stability of the octet. This makes calcium a Ca+2 cation.

Chlorine is a Halogen in the 17th column or s^2p^5s2p5 group.
Chlorine has 7 valence electrons. It needs one electron to make it stable at 8 electrons in its valence shells. This makes chlorine a Cl^(−1)Cl1 anion.

Ionic bonds form when the charges between the metal cation and non-metal anion are equal and opposite. This means that two Cl^(−1)Cl1 anions will balance with one Ca^(+2)Ca+2 cation.

This makes the formula for calcium chloride, CaCl_2CaCl2.

For the example Aluminum Oxide Al_2O_3Al2O3

Aluminum s^2p^1s2p1 has 3 valence electrons and an oxidation state of +3 or Al^(+3)Al+3
Oxygen s^2p^4s2p4 has 6 valence electrons and an oxidation state of -2 or O^(−2)O2

The common multiple of 2 and 3 is 6.
We will need 2 aluminum atoms to get a +6 charge and 3 oxygen atoms to get a -6 charge. When the charges are equal and opposite the atoms will bond as Al_2O_3Al2O3.

I hope this is helpful.
SMARTERTEACHER