Question

The antiparticle of electron is
A. Positron
B. $\alpha$-particle
C. proton
D. $\beta$-particle

Answer 1

Hint: An antiparticle of a given particle is defined as one which has the same mass as the particle but opposite charge compared to that of the particle. When an particle and antiparticle collide with each other, then they annihilate to produce energy.

Detailed step by step solution:
The electron is a negatively charged subatomic particle. Its charge and mass are given as
$\begin{array}{c}q=-1.6\times {10}^{-19}C\\ m=9.1\times {10}^{-31}kg\end{array}$
The symbol for electrons is $e^{-}$.
The electron is considered a particle. We also have an antiparticle for electron. An antiparticle is the opposite of a particle. The particle and antiparticle have same mass but opposite charge to each other.
The antiparticle of electron is called positron. It has same mass as that of electron but unlike electron, positron is positively charged and its symbol is $e^{+}$. It was discovered by Anderson.
Hence, the correct answer is option A.

Additional information:
The particles which have half-integral spins are known as fermions (e.g. electron, positron, proton, etc) while the particle with integral spins are known as bosons (e.g. photon).
The special fact about photon is that it is its own antiparticle. This is possible only in the case of bosons, fermions cannot be their own antiparticles.

Note: 1. The proton is not an antiparticle of electron because they have different masses. The antiparticle of proton is antiproton.
2. The beta particle is actually an electron which is created inside the nucleus and a fermion like electron cannot be its own antiparticle.
3. The alpha particle is actually a helium nuclei consisting of 2 protons and 2 neutrons only.