Which is the smallest part of an element that retains all of the properties of the element?

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

Answer: (A)

Verified step by step guidance

1. Understand the question: It asks for the smallest part of an element that retains all the properties of that element.
2. Recall the definitions of the options: A proton is a subatomic particle with a positive charge found in the nucleus; an electron is a negatively charged subatomic particle orbiting the nucleus; a molecule is a group of atoms bonded together; an atom is the smallest unit of an element that maintains the chemical properties of that element.
3. Analyze each option: Protons and electrons are parts of an atom but do not individually retain the full properties of the element. Molecules are combinations of atoms and may represent compounds or elements, but they are not the smallest unit of an element.
4. Conclude that the atom is the smallest unit that retains all the chemical properties of an element because it contains protons, neutrons, and electrons arranged in a way that defines the element's identity.
5. Therefore, the correct answer is the atom.