Which of the following is the smallest unit of an element that retains its chemical properties?

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

Answer: (B)

Verified step by step guidance

1. Understand the question: It asks for the smallest unit of an element that retains its chemical properties.
2. Recall the definitions: A proton is a subatomic particle found in the nucleus, an electron is a subatomic particle orbiting the nucleus, and a molecule is a group of atoms bonded together.
3. Identify the smallest unit that still retains the chemical properties of an element: This is the atom, which consists of protons, neutrons, and electrons but itself represents the element's chemical identity.
4. Recognize that molecules are made of two or more atoms bonded together, so they are larger than atoms and represent compounds or elemental forms but not the smallest unit.
5. Conclude that the atom is the smallest unit of an element that retains its chemical properties.