How many atoms of F are in the following formula: 3BaF2

1) 6
2) 3
3) 2
4) 5

Aballoon inflated with three breaths of air has a volume of 1.7 l. at the same temperature and pressure, what is the volume of the balloon if five more same-sized breaths are added to the balloon?

Calcium chloride +gold(1) oxide—>

If a polyatomic ionic compound has gained two hydrogen ions, then how does its name begin?