Atomic Nucleus Composition

Steps:

• Identify the atomic nucleus as the central core of an atom.
• Recall subatomic particles: protons (positive charge), neutrons (neutral), electrons (negative charge).
• Note electrons orbit the nucleus in electron clouds.
• Conclude nucleus contains only protons and neutrons for stability.

Why C is correct:

• By definition in atomic theory, the nucleus is composed solely of protons and neutrons, forming the atomic mass and charge center.

Why the others are wrong:

• A: Electrons reside outside the nucleus in orbitals, not within it.
• B: Protons are essential in the nucleus for atomic number and charge.
• D: Electrons are excluded from the nucleus; including them contradicts nuclear structure.

Final answer: C