Question

The nucleus of any atom is made up of

• A. proton
• B. proton and electron
• C. $\alpha$-particle
• D. proton and neutron

Hint:

Remember the basic structure of an atom: a central nucleus containing protons and neutrons, surrounded by a cloud of orbiting electrons. The number of protons defines the element, while the number of neutrons defines the isotope.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
This question asks about the composition of the atomic nucleus, which is the central, dense region of an atom.
Step 2: Detailed Explanation:
The nucleus of an atom is composed of two types of subatomic particles:
- Protons, which have a positive electrical charge.
- Neutrons, which are electrically neutral (have no charge).
These two particles, protons and neutrons, are collectively known as nucleons. They are held together in the nucleus by the strong nuclear force.
Let's analyze the other options:
- (A) proton: The nucleus contains protons, but for all elements except the most common isotope of hydrogen (protium), it also contains neutrons. So this is incomplete.
- (B) proton and electron: Electrons are negatively charged particles that orbit the nucleus; they are not part of the nucleus itself.
- (C) $\alpha$-particle: An alpha particle is the nucleus of a helium atom, consisting of two protons and two neutrons. While it is a type of nucleus, not all atomic nuclei are α-particles.
Step 3: Final Answer:
The nucleus of an atom is made up of protons and neutrons. Therefore, option (D) is the correct answer.