Question

What is the composition of an $\alpha$
particle?

• A. 2 protons and 2 neutrons only
• B. 2 electrons, 2 protons and 2 neutrons
• C. 2 electrons and 4 protons only
• D. 2 protons only

Answer 1

The correct option is A 2 protons and 2 neutrons only

α-particle is nucleus of helium ($2H{e}^4$)
Number of protons = 2
Number of neutrons = A − Z = 4 − 2 = 2