$\alpha$ -particle consists of:

An $\alpha$ -particle is a Helium nucleus (${}_2^{4}H{e}^{2+}$).It is produced by removing both electrons from a Helium atom.Atomic number $Z=2⟹2$ protons.Mass number $A=4⟹$ neutrons $=A-Z=2$ neutrons.Since it is a nucleus, it contains no electrons.