Question

which of the following answer choices is not a compound? nacl si pbso hmg

Explanation:

Step1: Recall compound definition

A compound is a substance made up of two or more different elements chemically combined.

Step2: Analyze each option

• NaCl is sodium chloride, a compound of sodium (Na) and chlorine (Cl).
• Si is silicon, an element, not a compound as it consists of only one type of atom.
• PbSO is an incorrect formula, but if we assume it's a compound - like lead - sulfate which would be made of lead (Pb), sulfur (S) and oxygen (O).
• HMg is an incorrect formula, but if we assume it's a compound - it would be made of hydrogen (H) and magnesium (Mg).

Answer:

Si