Which of the following best describes the difference between atoms and molecules?

• A. Atoms are single units of elements, while molecules are combinations of two or more atoms bonded together.
• B. Atoms are always larger than molecules.
• C. Molecules are made up of only one type of atom.
• D. Atoms can only exist as part of a molecule.

Answer: (A)

Verified step by step guidance

1. Step 1: Understand the definition of an atom. An atom is the smallest unit of an element that retains the chemical properties of that element. It consists of protons, neutrons, and electrons.
2. Step 2: Understand the definition of a molecule. A molecule is formed when two or more atoms chemically bond together. These atoms can be of the same element or different elements.
3. Step 3: Compare atoms and molecules based on their composition. Atoms are single units, while molecules are combinations of atoms bonded together.
4. Step 4: Evaluate the given options by applying these definitions. For example, atoms are not always larger than molecules; molecules can be made of different types of atoms, and atoms can exist independently (like noble gases).
5. Step 5: Conclude that the best description is that atoms are single units of elements, while molecules are combinations of two or more atoms bonded together.