The chemical formula of Sodium nitrite

The quantity of valence electrons must be written down, exchanged with the appropriate component, and then written as the subscript in order to create the chemical formula for sodium nitrate. Ionic contact, or the link between Na (+1) and NO3(-1) ions, results in the formation of sodium nitrate.

The symbols for each element or ion that combine to create a compound's molecule must be written down side by side before the chemical formula can be written. The sign for the metal is written first, followed by the symbol for the non-metal, when writing the formula of a compound comprising a metal and a non-metal. Here, it's important to remember that two metals do not combine to produce compounds. Then, indicate how many valence electrons are present in each element or ion. Change the element valencies, then write it as a subscript. Write them close together and ignore 'l' to obtain the formula. The radical polyatomic ions must be written in brackets before the subscript is written.

If there are just one polyatomic ion, the bracket is not necessary. When appropriate, put down the valencies' simple ratios. The final formula must be written completely free of any charges.
By doing these processes, we may determine that Na is the symbol for sodium and that NO₂ is the nitrite formula. Combining the two results in the formula NaNO₂, which stands for sodium nitrite.

Hence, option A is correct.