Question

3 which statement best describes atoms according to modern atomic theory? a they are solid blocks b they are perfectly uniform in all elements c they have internal structure and vary in mass d they are hollow spheres

Explanation:

• Option A: Modern atomic theory shows atoms are not solid blocks. They have sub - atomic particles like protons, neutrons, and electrons.
• Option B: Atoms of different elements have different numbers of protons, neutrons, etc., so they are not perfectly uniform.
• Option C: Modern atomic theory (e.g., Bohr's model, quantum mechanical model) indicates atoms have internal structure (nucleus with protons and neutrons, and electrons in orbitals). Also, atoms of different elements (isotopes too) vary in mass.
• Option D: Atoms are not simply hollow spheres. The quantum mechanical model describes electron probability distributions rather than a simple hollow - sphere structure.

Answer:

C. They have internal structure and vary in mass