Which subatomic particle is massive and located at the center of the atom?

• A. Proton
• B. Photon
• C. Neutron
• D. Electron

Answer: (A)

Verified step by step guidance

1. Recall the structure of an atom, which consists of a nucleus at the center and electrons surrounding it in orbitals.
2. Identify the subatomic particles found in the nucleus: protons and neutrons. Both are relatively massive compared to electrons.
3. Understand that electrons are much lighter and are located outside the nucleus, in the electron cloud.
4. Recognize that photons are not subatomic particles within the atom; they are particles of light and do not have mass or a fixed position in the atom.
5. Conclude that the massive subatomic particles located at the center of the atom are protons and neutrons, but since the question asks for a single particle and the correct answer is 'Proton', focus on the proton as the positively charged, massive particle in the nucleus.