Which statement best describes the difference between atoms and molecules?

• A. Atoms and molecules have identical chemical properties.
• B. Molecules are made up only of neutrons, while atoms contain protons and electrons.
• C. Atoms are always larger than molecules.
• D. Atoms are single particles consisting of protons, neutrons, and electrons, while molecules are combinations of two or more atoms bonded together.

Answer: (D)

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, creating a distinct chemical substance.
3. Step 3: Compare atoms and molecules based on their composition. Atoms are single particles, while molecules are combinations of atoms bonded together.
4. Step 4: Recognize that atoms and molecules differ in size and complexity. Molecules are generally larger and more complex because they contain multiple atoms.
5. Step 5: Conclude that the key difference is that atoms are individual units, whereas molecules are groups of atoms bonded together, which explains their different chemical properties and structures.