4. Which of the following materials is necessary to stop a beta particle? (1 point)
three feet of concrete
three inches of lead
thin pieces of wood
single sheet of paper
5. A neutron breaks down to form _____. (1 point)
an alpha particle
two protons
a proton and an electron
a helium nucleus
6. What does the band of stability for atomic nuclei refer to? (1 point)
the ratio of protons to neutrons
the ratio of neutrons to protons
the ratio of beta particles to neutrinos
the ratio of alpha particles to beta particles