Can some teach me how to find the formula please:( I give medal too

Question

ibrafacts · Answer

i have a test tomorrow someone please teach m

frostbite · Answer

Is it a), c) and d) causing issues?

ibrafacts · Answer

yeah

ibrafacts · Answer

i mean if u teach me how t do a i try b and c again and u check it

frostbite · Answer

I like that! (you are the first person who haven't just wanted an answer AKA I like you per definition!)

Okay:
a) Barium makes a divalent cation (2+), while oxygen makes a divalent kation (2-).
We make this deduction on the idea that both barium and oxygen wants perfect gas configuration, thus barium needs to lose 2 electrons and oxygen needs to gain 2 electrons as you can see in the periodic table. The whole compound need to be electronic neutral (no charge) thus we can get the stoichiometry of the molecule to be:
BaO

ibrafacts · Answer

how do u know oxygen is +2?

ibrafacts · Answer

i showed u my periodic table it doesnt say it

frostbite · Answer

How many electrons does oxygen need to obtain perfect gas electron configuration?

ibrafacts · Answer

Oh I see never it says -2

ibrafacts · Answer

My bad

frostbite · Answer

No problem. Just think like that when you do ionic compounds as rule of thumb.

ibrafacts · Answer

so its|dw:1453167019161:dw|