Question

which of the following makes up a molecule of water?
one atom of hydrogen and one atom of oxygen
one atom of sodium and one atom of chlorine
one atom of hydrogen and two atoms of oxygen
two atoms of hydrogen and one atom of oxygen

Explanation:

Step1: Recall the chemical formula of water

The chemical formula of water is \(H_2O\).

Step2: Analyze the formula

In \(H_2O\), the subscript 2 indicates there are 2 hydrogen (\(H\)) atoms, and the subscript 1 (usually omitted) for \(O\) indicates 1 oxygen atom.

Answer:

two atoms of hydrogen and one atom of oxygen