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

• A. A molecule consists of two or more atoms chemically bonded together, while an atom is a single unit of an element.
• B. A molecule contains protons and neutrons, while an atom contains only electrons.
• C. A molecule is always electrically charged, while an atom is always neutral.
• D. A molecule is smaller than an atom.

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 a nucleus containing protons and neutrons, surrounded by 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 two definitions. An atom is a single unit, while a molecule is a group of atoms bonded together.
4. Step 4: Evaluate the given options based on these definitions. The correct description should highlight that a molecule consists of two or more atoms chemically bonded, whereas an atom is a single unit.
5. Step 5: Conclude that the best description is: 'A molecule consists of two or more atoms chemically bonded together, while an atom is a single unit of an element.'