Question

will give medal please help

Answer 1

How many atoms of oxygen are in one formula unit of Ca(NO3)2?

Answer 2

You just have to count how many oxygen atoms are in the formula. So as you can see, O has a '3' next to it, meaning there are 3 oxygen atoms. However the NO3 is in brackets with a 2 next to the brackets. This means 'times two', so its 3 x 2 which equals 6 oxygen atoms.

If you get confused with the brackets, it basically means NO3 NO3 (two lots of them as the number next to the bracket is two)

I hope this helps :)

Answer 3

awsome ty

Answer 4

l