Question

Complete the following sentence :

During the emission of a beta particle, the .......... number remain same.

• A. $atomic$
• B. $mass$
• C. $neutron$
• D. None of the above

Answer 1

The correct option is B $mass$

In beta decay mass number of atom remains unchanged, but atomic number changes by $1$. In beta decay either neutron decays into proton, or a proton decays in neutron, so overall mass number remains same.