The nucleus of an atom consists of?

1. Analyze the question

The question asks for the subatomic particles that make up the central core (nucleus) of an atom.

2. Explain the concept

An atom is composed of three main subatomic particles:

• Protons: Positively charged particles found inside the nucleus.
• Neutrons: Neutral particles (no charge) also found inside the nucleus.
• Electrons: Negatively charged particles that orbit the nucleus in specific energy levels or shells.

The nucleus is the dense, central part of the atom where almost all of its mass is concentrated. Because protons and neutrons are located here, they are collectively referred to as nucleons.

3. Show the solution

• Step 1: Identify the location of electrons. Electrons are located in the shells (or orbitals) surrounding the nucleus, not inside it. This eliminates options A and B.
• Step 2: Identify the location of protons and neutrons. Protons and neutrons are tightly packed together at the center of the atom, forming the nucleus.
• Step 3: Compare with the given options. Since the nucleus contains only protons and neutrons, option C is the correct description.

4. Identify the answer

The correct option is C.

5. Exam Tip

To remember this easily, use the mnemonic "P-N" for Protons and Neutrons in the Nucleus. Think of the nucleus as the "heavy" part of the atom; since electrons have negligible mass compared to protons and neutrons, they stay outside the nucleus, while the "heavy" particles stay inside.