Question

Among the following, which one is not the fundamental particle?

• A. Positron
• B. Electron
• C. \( \alpha \)-particle
• D. Neutrino

Hint:

Fundamental particles are indivisible and not made up of smaller particles, such as electrons, neutrinos, and positrons.

Answer 1

The Correct Option is C

Step 1: Understanding Fundamental Particles.
Fundamental particles are those particles that are not made up of smaller particles. Examples include electrons, positrons, and neutrinos, which are considered elementary particles. In contrast, \( \alpha \)-particles are not fundamental as they are composed of two protons and two neutrons, meaning they are composite particles.
Step 2: Analysis of options.
- (A) Positron: A positron is the antiparticle of the electron, and it is a fundamental particle.
- (B) Electron: An electron is an elementary particle, meaning it is fundamental.
- (C) \( \alpha \)-particle: An \( \alpha \)-particle consists of two protons and two neutrons, so it is not fundamental. It is a composite particle.
- (D) Neutrino: A neutrino is an elementary particle and hence a fundamental particle.

Step 3: Conclusion.
The \( \alpha \)-particle is not a fundamental particle, making option (C) the correct answer.