1. How does an atom's nucleus stay together and remain stable?
(a) The attractive gravitational force between the protons and neutrons overcomes the repulsive electrostatic force between the protons.
(b) Having just the right number of neutrons overcomes the electrostatic force between the protons.
(c) A strong covalent bond develops between the neutrons and protons, because they are so close to each other.
(d) None of the above.
2. What has greater mass?
(a) A neutron and a proton that are far from each other (unbound).
(b) A neutron and a proton that are bound together in a hydrogen (deuterium) nucleus.
(c) Both the same.