Which statement best describes atoms?

• A. Atoms are composed only of protons and neutrons.
• B. Atoms are the smallest units of matter that retain the properties of an element.
• C. Atoms are always electrically charged.
• D. Atoms can be divided into smaller particles by ordinary chemical reactions.

Answer: (B)

Verified step by step guidance

1. Understand the definition of an atom: An atom is the smallest unit of matter that retains the chemical properties of an element.
2. Recall the composition of atoms: Atoms consist of protons, neutrons, and electrons, not just protons and neutrons.
3. Recognize that atoms are electrically neutral overall because the number of protons (positive charge) equals the number of electrons (negative charge).
4. Know that atoms cannot be divided into smaller particles by ordinary chemical reactions; such reactions involve rearranging atoms, not breaking them apart.
5. Conclude that the best description is that atoms are the smallest units of matter that retain the properties of an element.