Which of the following does NOT accurately describe the forces that exist within an atom?

• A. Electrons are attracted to the nucleus by electrostatic (Coulombic) forces.
• B. Electrons are held in the atom by gravitational attraction to the nucleus.
• C. Repulsion between protons in the nucleus is counteracted by the strong nuclear force.
• D. Protons and neutrons in the nucleus are held together by the strong nuclear force.

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the types of forces acting within an atom. The main forces include electrostatic (Coulombic) forces between charged particles and the strong nuclear force within the nucleus.
2. Step 2: Recognize that electrons are negatively charged and the nucleus is positively charged due to protons, so electrons are attracted to the nucleus by electrostatic forces, not gravitational forces.
3. Step 3: Recall that gravitational forces between subatomic particles are negligible because their masses are extremely small, making gravitational attraction insignificant compared to electrostatic forces.
4. Step 4: Know that protons repel each other due to their positive charges, but this repulsion is overcome by the strong nuclear force, which acts only at very short ranges within the nucleus.
5. Step 5: Confirm that protons and neutrons are held together in the nucleus by the strong nuclear force, which is much stronger than electrostatic repulsion at the nuclear scale.