which is an electron? a b c

Brief Explanations:

In an atomic model, electrons are negatively - charged particles that orbit the nucleus. In the given diagram, the particles orbiting the central nucleus are electrons.

Answer:

A. Option Text, B. Option Text, C. Option Text (Since no text for options A, B, C is given in the question itself, we assume the options are just labeled as such and based on the typical atomic - model understanding, the particles orbiting the nucleus are electrons. Without seeing which of A, B, C corresponds to the orbiting particles in the diagram, we can't give a more specific answer. But conceptually, the electrons are the ones in orbit around the nucleus).