Which of the following is considered the smallest possible unit of matter that retains the properties of an element?

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

Answer: (A)

Verified step by step guidance

1. Understand the question is asking for the smallest unit of matter that retains the properties of an element.
2. Recall that an element is defined by its atoms, which are the basic building blocks of matter for that element.
3. Recognize that electrons and protons are subatomic particles, which are components of atoms but do not individually retain the properties of the element.
4. Note that molecules are combinations of two or more atoms bonded together, so they are larger than atoms and may represent compounds or elements depending on the atoms involved.
5. Conclude that the atom is the smallest unit that still retains the chemical properties of an element.