Question

part a
in a chemical formula, how do you calculate the number of atoms of an element within parentheses?
by multiplying the parentheses subscript by the subscript of each element within the parentheses.
by summing the parentheses subscript with the subscript of each element within the parentheses.
by dividing the parentheses subscript by the subscript of each element within the parentheses.

Explanation:

In a chemical formula, when calculating the number of atoms of an element within parentheses, we use multiplication. For example, in the formula \(Ca(NO_3)_2\), for the oxygen atoms: the subscript of \(O\) is \(3\) (within the parentheses) and the subscript outside the parentheses is \(2\). We multiply these two values (\(3\times2 = 6\)) to get the total number of oxygen atoms.

Answer:

By multiplying the parentheses subscript by the subscript of each element within the parentheses.