Answer:

Explanation:
The first step is the <u>calculation of the moles</u> of
and
, so:


Now, in 1 mol of CO2 we have 1 mol of C and in 1 mol of
we have 1 mol of H. Additionally, if we want to calculate the moles of oxygen we need to <u>calculate the grams of C and O</u> and then do the <u>substraction</u> form the initial amount, so:


Now we can <u>convert the grams</u> of O to moles, so:

The next step is to divide all the mol values by the <u>smallest one</u>:



Therefore the formula is 
It’s Nitrogen (N) with a -3 charge
Nitrogen, Oxygen, and Fluorine do not follow this trend. The noble gas electron configuration will be close to zero because they will not easily gain electrons.