Question

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

Explanation:

In a chemical formula, when there are parentheses, the subscript outside the parentheses multiplies the subscript of each element inside the parentheses. For example, in \(Ca(OH)_2\), for the \(O\) atom: there is \(1\) \(O\) inside the parentheses and the subscript outside is \(2\), so the number of \(O\) atoms is \(1\times2 = 2\); for the \(H\) atom: there is \(1\) \(H\) inside the parentheses and the subscript outside is \(2\), so the number of \(H\) atoms is \(1\times 2=2\). Dividing or summing does not give the correct number of atoms in this context.

Answer:

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