Question

How many sub-atomic particles are present in an $\alpha$- particle used in Rutherford's scattering experiment?

• A. Protons - 4, Neutrons - 0, Electrons - 0
• B. Protons - 2, Neutrons - 0, Electron - 2
• C. Protons - 2, Neutron - 2, Electron - 0
• D. Protons - 2, Neutron - 2, Electron - 1

Answer 1

Answer: (C)

Protons - 2, Neutron - 2, Electron - 0

$\alpha$ particle is identical to a helium atom that has been lost its two electrons.
no. of $e^{-}=0$

no. of proton $=2$

no. of neutron $=2$

Hence, the correct option is $\text{C}$.