How can you determine formula of an a ionic molecule?
Lets take the ionic formula for Calcium Chloride is
Calcium is an Alkaline Earth Metal in the second column of the periodic table. This means that calcium has 2 valence electrons it readily gives away in order to seek the stability of the octet. This makes calcium a
Chlorine is a Halogen in the 17th column or
Chlorine has 7 valence electrons. It needs one electron to make it stable at 8 electrons in its valence shells. This makes chlorine a
Ionic bonds form when the charges between the metal cation and non-metal anion are equal and opposite. This means that two
This makes the formula for calcium chloride,
For the example Aluminum Oxide
Aluminum has an oxidation state of +3 or
Oxygen has an oxidation state of -2 or
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