Given in the question the following data;
- Mass number, A = 37
- Atomic number, Z = 17
- Number of protons = Atomic number = 17
Note:
- Atomic number indicates the total number of protons or electrons.
Z = no. of protons / electrons
- Atomic mass number indicates the sum of protons and neutrons.
A = P + N
However, had the question been to find the number of Neutrons, we could find it by subtracting the atomic number from its mass number.
ie,
Number of Neutrons = A - Z
= 37 - 17
= 20
