Which fundamental force is primarily responsible for holding together the protons and neutrons within an atom's nucleus?

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

Answer: (D)

Verified step by step guidance

1. Understand that the question asks about the force that holds protons and neutrons together inside the nucleus of an atom.
2. Recall that protons are positively charged and would repel each other due to the electromagnetic force if no other force acted to hold the nucleus together.
3. Recognize that gravitational force is extremely weak at the scale of subatomic particles and cannot account for the stability of the nucleus.
4. Know that the weak nuclear force is responsible for certain types of radioactive decay but does not hold the nucleus together.
5. Identify the strong nuclear force as the fundamental force that overcomes the electromagnetic repulsion between protons and binds protons and neutrons tightly within the nucleus.