Which of the following best describes an atom?

• A. A positively charged particle found in the nucleus of an atom.
• B. A negatively charged particle that orbits the nucleus of an atom.
• C. A small particle consisting of a nucleus containing protons and neutrons, surrounded by electrons in energy levels.
• D. A molecule made up of two or more different elements chemically bonded together.

Answer: (C)

Verified step by step guidance

1. Understand that an atom is the basic unit of a chemical element, consisting of a central nucleus and electrons surrounding it.
2. Recall that the nucleus contains positively charged protons and neutral neutrons, which together account for most of the atom's mass.
3. Recognize that electrons are negatively charged particles that occupy specific energy levels or orbitals around the nucleus.
4. Distinguish an atom from subatomic particles: a proton is a positively charged particle in the nucleus, and an electron is a negatively charged particle orbiting the nucleus.
5. Differentiate an atom from a molecule, which is a combination of two or more atoms chemically bonded together.