Question

4.
When an Alpha ray is emitted:
* atomic number is decreased by 2 & mass number is decreased by 4.
* atomic number remains same & mass number is decreased by 2.
* atomic number is decreased by 1 & mass number is decreased by 2.
* atomic number is increased but mass number remains same.​

Answer 1

Answer:

atomic number is decreased by 2 & mass number is decreased by 4.

Explanation:

This is because alpha particles contain Helium which has the atomic number 2 and mass number 4.

Therefore when emitted, it decreases atomic number by 2 and decreases mass number by 4.