Which of the following is a characteristic of the nucleus (the part of the atom marked "a")?

• A. It contains protons and neutrons.
• B. It occupies most of the atom's volume.
• C. It is negatively charged.
• D. It is where electrons are found.

Answer: (A)

Verified step by step guidance

1. Recall the basic structure of an atom, which consists of a nucleus and electrons surrounding it.
2. Understand that the nucleus is the central part of the atom and contains subatomic particles called protons and neutrons.
3. Remember that protons carry a positive charge, neutrons have no charge, and electrons are negatively charged particles found outside the nucleus.
4. Recognize that the nucleus occupies a very small volume compared to the entire atom, but it contains most of the atom's mass.
5. Conclude that the nucleus is positively charged overall (due to protons) and does not contain electrons, so the correct characteristic is that it contains protons and neutrons.