Final answer:
The correct coefficient for sodium nitrate is 1, as the chemical formula NaNO3 indicates one sodium ion bonded to one nitrate ion.
Step-by-step explanation:
The correct whole number coefficient for sodium nitrate is B. 1. In chemistry, when we write the formula for a compound and do not include a numerical coefficient, it is understood to be 1. Sodium nitrate is formed by one sodium ion (Na+) and one nitrate ion (NO3−), making the chemical formula NaNO3. There is no need for any coefficient other than 1 when referring to a single formula unit of a compound in a balanced chemical equation or when representing its formula.