Which of the following is considered the smallest basic unit of matter?

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

Answer: (C)

Verified step by step guidance

1. Understand the question: It asks for the smallest basic unit of matter among the given options.
2. Recall definitions: An electron is a subatomic particle with a negative charge, a proton is a positively charged subatomic particle, a molecule is a group of atoms bonded together, and an atom is the smallest unit of an element that retains its chemical properties.
3. Analyze the options: Electrons and protons are parts of an atom, but they are not considered units of matter by themselves; molecules are made of atoms combined.
4. Conclude that the atom is the smallest basic unit of matter because it is the fundamental building block of elements and matter.
5. Therefore, the correct answer is 'Atom' as it represents the smallest unit that retains the properties of an element.