Question

the 2 that was added in front of the h2o molecule is known as a
coefficient
subscript

Explanation:

In chemical formulas, a coefficient is a number placed in front of a molecule. It indicates the number of that molecule. For example, in \(2H_2O\), the \(2\) is a coefficient meaning there are 2 water molecules. A subscript is a number written below and to the right of an element symbol in a chemical formula. It shows the number of atoms of that element in the molecule. For example, in \(H_2O\), the \(2\) is a subscript indicating 2 hydrogen atoms.

Answer:

Coefficient