Chemical Forums
Chemistry Forums for Students => High School Chemistry Forum => Topic started by: appleseed on February 28, 2009, 08:36:52 AM

If you know the outer number of electrons there are on an atom can you find its formula?
If you have and atom X with 4 outer electrons
and Y with 5 outer electrons do you just swap the numbers round to find the formula of its compound?
so i end up with X5Y4?
Or is this the way to find an ionic formula?
ThankYOu!

It generally works for ionic compounds.

hmm, the question says that its covalent
so what should i do?

Could you please clarify what the question is?

ok the question is deduce the formula of a covalently bonded compound that contains X (with 4 outer electrons ) and Y with 6 outer electrons.
I was just wondering if there's a general formula or rule that can help me deduce the formula with any number of electrons

Swapping should work, and you should cancel out the common factors.
So,it is
X_{3}Y_{2}
This,Ithink, is the answer..

in my opinion it's easier to take examples...if it's a covalent bond, take for example carbon and oxygen,they will form CO_{2},so it's XY_{2}...but if the bond is ionic than it's X_{6}Y_{4}=X_{3}Y_{2}