Answer: electron
Explanation: An atom is made up of three fundamental particles: electron, proton and neutron. Electrons have negative charges, protons have positive charges while neutrons have no charge. The number of electrons is equal to the number of protons thus making an atom electrically neutral. Protons and neutrons are located inside the nucleus of an atom while electrons are located outside the nucleus where they revolve round the nucleus in their orbits.
The answer is c when the substances are evenly spread out.
Proterozoic is the answer.
