Question

Complete the following :

Mercury contains 80 protons and 80 electrons and 120 neutrons. Its mass number is ___________.

Answer 1

Mercury contains 80 protons and 80 electrons and 120 neutrons. Its mass number is 200.

As we know:

$$\begin{gathered} \mathrm{Mass}\mathrm{number}=\mathrm{Total}\mathrm{number}\mathrm{of}\mathrm{protons}+\mathrm{Total}\mathrm{number}\mathrm{of}\mathrm{neutrons} \\ \mathrm{Mass}\mathrm{number}\mathrm{of}\mathrm{mercury}=80+120 \\ \mathrm{Mass}\mathrm{number}\mathrm{of}\mathrm{mercury}=200 \end{gathered}$$