Question

almost all the mass of an atom is concentrated in the .
options: electrons, protons, nucleus, neurons, alpha particles

Explanation:

An atom consists of a nucleus (containing protons and neutrons) and electrons. Electrons have negligible mass compared to protons and neutrons. The nucleus, which contains protons and neutrons, holds almost all the mass of an atom because protons and neutrons have significant mass, while electrons contribute very little.

Answer:

C. nucleus