N2O5 is Dinitrogen pentoxide anytime you have two non metals group together you will have to use a prefix at the beginning of each one prefixes are based on mathematical terms such as
Mono=1
Di=2
Tri=3
tetra=4
penta=5
hexa=6
and so forth basically using the mathematical shapes names you learned in elementary school
when naming the anion or the last element of a binary compund a compound of two elements we change the ending by dropping the last few letters and out in ide for example nitride is nitrogen
oxide is oxygen and chloride is chlorine to name a few
When naming metal salts we use the metals charge and the anions name with the ions name
example
Ti+4cl=TiCl4
This compounds name is Titanium IV Chloride same with all metals combined with non metals
