Question

What is the mass number of zinc?

Answer 1

Step 1. Formula for mass number:

$\text{Mass number}\left(\text{A}\right)=\text{number of protons}\left(\text{Z}\right)+\text{number of neutrons}\left(\text{n}\right)$

Step 2. Mass number of zinc $\left(\mathrm{Zn}\right)$:

• The number of protons in Zinc is $30$.
• The number of neutrons in Zinc is $35$.
• So using the above formula, the mass number of zinc $=30+35=65$

Thus, the mass number of zinc is $65$.