What does NaH represent?

NaH represents sodium hydride, which is a binary compound formed from sodium (Na) and hydrogen (H). In this formula, sodium has a +1 charge because it is an alkali metal, and hydride has a -1 charge, allowing the two ions to combine in a 1:1 ratio to form the neutral compound NaH.

In terms of nomenclature, the naming convention for ionic compounds typically involves stating the name of the metal cation first (in this case, sodium) followed by the name of the non-metal anion (hydride, which is the hydrogen anion). This is consistent with the rules for naming simple ionic compounds.

The other choices represent different compounds made from sodium and other anions. Sodium hydroxide, for example, contains the hydroxide ion (OH⁻) and is represented as NaOH, while sodium bromide consists of bromide (Br⁻) and would be represented as NaBr. Sodium phosphate involves a more complex polyatomic ion, phosphate (PO₄³⁻), resulting in Na₃PO₄ instead. Understanding the proper nomenclature and corresponding chemical formulas is crucial in identifying which compound is represented by a given chemical formula.