Which type of force holds protons and neutrons together in the nucleus of an atom?

• A. Strong nuclear force
• B. Weak nuclear force
• C. Electromagnetic force
• D. Gravitational force

Answer: (A)

Verified step by step guidance

1. Understand that the nucleus of an atom contains protons and neutrons, which are collectively called nucleons.
2. Recall that protons are positively charged and would repel each other due to the electromagnetic force if no other force acted between them.
3. Identify that the force responsible for overcoming this repulsion and holding protons and neutrons tightly together in the nucleus is a fundamental force known as the strong nuclear force.
4. Note that the strong nuclear force acts only at very short ranges (on the order of femtometers) and is much stronger than the electromagnetic force within this range.
5. Recognize that the weak nuclear force and gravitational force do not play a significant role in holding the nucleus together; the weak force is involved in radioactive decay, and gravity is negligible at the nuclear scale.