Which of the following statements best describes the basic structure of an atom?

• A. An atom consists of a dense nucleus containing protons and neutrons, surrounded by electrons in a cloud.
• B. An atom is a solid sphere composed entirely of neutrons.
• C. An atom consists of a nucleus made only of electrons, with protons and neutrons orbiting around it.
• D. An atom is made up of only electrons and protons distributed evenly throughout its volume.

Answer: (A)

Verified step by step guidance

1. Recall the fundamental model of an atom, which includes a central nucleus and electrons surrounding it.
2. Understand that the nucleus contains protons and neutrons, which are densely packed together.
3. Recognize that electrons are much lighter and occupy a region around the nucleus often described as an electron cloud, not fixed orbits.
4. Eliminate incorrect statements: atoms are not solid spheres of neutrons, nor do electrons form the nucleus, nor are protons and electrons evenly distributed throughout the atom.
5. Conclude that the best description is that an atom consists of a dense nucleus containing protons and neutrons, surrounded by electrons in a cloud.