Which of the following best describes the smallest particle of an element that can exist?

• A. Proton
• B. Atom
• C. Molecule
• D. Electron

Answer: (B)

Verified step by step guidance

1. Understand the question is asking about the smallest particle of an element that can exist independently.
2. Recall that a proton is a subatomic particle found inside the nucleus of an atom, but it cannot exist independently as an element.
3. Recognize that an electron is also a subatomic particle orbiting the nucleus, but it alone does not represent an element.
4. Know that a molecule is made up of two or more atoms bonded together, so it is not the smallest particle of an element.
5. Conclude that an atom is the smallest particle of an element that retains the chemical properties of that element and can exist independently.