Which of the following best describes the difference between an atom and a molecule?

• A. An atom is always larger than a molecule.
• B. An atom is a single particle consisting of protons, neutrons, and electrons, while a molecule is a group of two or more atoms chemically bonded together.
• C. Atoms are formed by the combination of molecules.
• D. A molecule contains only one type of element, while an atom contains multiple types of elements.

Answer: (B)

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 the size and composition. An atom is a single particle, while a molecule is a group of atoms bonded together, so a molecule is generally larger than a single atom.
4. Step 4: Analyze the given options based on these definitions. The correct description should highlight that an atom is a single particle, and a molecule is a group of atoms bonded together.
5. Step 5: Conclude that the best description is: 'An atom is a single particle consisting of protons, neutrons, and electrons, while a molecule is a group of two or more atoms chemically bonded together.'