Answer:
B) a neutron
Step-by-step explanation:
The mass of a proton is approximately the mass of a neutron.
Both a neutron and proton are nuclear particles that are found within the nucleus of an atom.
Protons are the positively charged particles within an atom.
Neutrons do not have any charges on them.
Approximately the mass of:
Protons = 1.67 x 10⁻²⁷kg
Neutrons = 1.68 x 10⁻²⁷kg