Question

What happens if you change a subscript in a correctly written chemical formula?

Answer 1

You end up discussing an entirely different compound, one that may or may not exist in reality.

For example, `"NO"_2` exists. `"N"_2"O"` exists. `"N"_2"O"_5` exists. `"N"_37"O"_2` surely does not, because it would be ridiculous to have 37 nitrogen atoms attached to only two oxygens.

A chemical formula defines what a compound's composition is. Alter the subscripts and you completely change what the compound is...