Question

I need help with Ionic Bonding/Formulas!
http://gyazo.com/2197c6c8a400a0e0fd639c865eccbdf3
Explain how you got your answer please.

Answer 1

CaBr2 Ca has a charge of 2+ br - , the point of ionic bonding or molecular bonding is to be stable, which also means it needs to be electrostatic-ally neutral. to have the ionic bond neutral use must have an equal amount of positive chrage to cancel with the two minus. so since Br is just one minus, if you add another Br ion, it would be 2-. ok now, since you did nothing to the Ca to change it it stays as Ca no subscripts no nothing. Br since you added two, its gonna be Br2

put them together and it becomes CaBr2