Question

what is the formula mass of a compound?
it is the sum of the atomic mass of all elements in the chemical formula.
it is the atomic mass of all metals in the chemical formula.
it is the atomic mass of all non - metals in the chemical formula.

Explanation:

The formula mass of a compound is defined as the sum of the atomic masses of all the atoms (from all elements, both metals and non - metals) present in its chemical formula, considering the number of each type of atom. The second option is incorrect as it only considers metals, and the third option is incorrect as it only considers non - metals.

Answer:

A. It is the sum of the atomic mass of all elements in the chemical formula.