Answer:
NaNO₂
Step-by-step explanation:
The question asks for the chemical formula of sodium nitrite, which can be determined based on the constituent ions and their charges.
Sodium nitrite consists of sodium (Na) and nitrite (NO₂) ions.
1. Sodium (Na): This is an alkali metal found in Group 1 of the periodic table, and when it forms ions, it typically loses one electron to have a charge of +1. Thus, its ionic form is represented as Na⁺.
2. Nitrite (NO₂): The nitrite ion is a polyatomic ion consisting of nitrogen and oxygen, and it carries a -1 charge. Thus, it is represented as NO₂⁻.
To form a stable compound, the positive and negative charges must balance out. In this case, one sodium ion (Na⁺) with a +1 charge will combine with one nitrite ion (NO₂⁻) with a -1 charge to form a neutral compound.
Based on the above reasoning, the chemical formula for sodium nitrite is NaNO₂.