Question

$\alpha$-particle consists of:

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

Answer 1

The Correct Option is C

An alpha ($\alpha$) particle is a type of atomic nucleus. Understanding its composition is crucial in nuclear physics and helps in various applications such as radioactive decay processes.

Let's analyze the given options to determine the correct composition:

1. Option 1: 2 electrons and 4 protons only

   This option describes a particle with more protons than any known stable nucleus and includes electrons. Alpha particles do not have electrons; hence, this option is incorrect.

2. Option 2: 2 protons only

   Alpha particles consist of more than just protons. They also contain neutrons. Therefore, this option is incorrect.

3. Option 3: 2 protons and 2 neutrons only

   This option is correct. An alpha particle is essentially a helium-4 nucleus, which consists of 2 protons and 2 neutrons. It is also represented as ^4_2\text{He}.

4. Option 4: 2 electrons, 2 protons, and 2 neutrons

   This option includes electrons. However, alpha particles do not contain electrons; they are made up solely of protons and neutrons. Thus, this option is incorrect.

Therefore, the correct answer is that an alpha ($\alpha$) particle consists of 2 protons and 2 neutrons only.

In summary, understanding the composition of particles like alpha particles is essential for various exams and knowledge in physics, especially for questions related to nuclear reactions and radioactivity.