Question

1. the mass number is used to calculate the number of _______________ in one atom of an element. in order to calculate the number of neutrons you must subtract the _____________ from the _______________.

Explanation:

1. Recall the concept of atomic structure: Mass number (A) is the sum of protons and neutrons in an atom. Atomic number (Z) is the number of protons.
2. To find neutrons, use the formula: Number of neutrons = Mass number - Atomic number.
3. So, mass number is used to calculate protons + neutrons (nucleons). For neutrons, subtract atomic number (protons) from mass number.

Answer:

The mass number is used to calculate the number of \underline{nucleons (protons + neutrons)} in one atom of an element. In order to calculate the number of neutrons you must subtract the \underline{atomic number (number of protons)} from the \underline{mass number}.