The molecular formula for silver nitrite is written as AgNO2. Ag is the chemical symbol for silver, N is the chemical symbol for nitrogen and O is the chemical symbol for oxygen.
When combined together, one atom of nitrogen and two atoms of oxygen bond together to create nitrite, which has a charge of -1. The -1 charge of the nitrite balances the +1 charge of the silver ion, which means the total compound has a neutral charge. The formula for silver nitrate is written as AgNO3 because the nitrate combines one atom of nitrogen with three atoms of oxygen.