P.12.A.8 - Students know most elements have two or more isotopes, some of which have practical applications. Able to know that isotopes of an element have the same number of protons, but differing numbers of neutrons. Able to identify that practical applications of isotopes arise from the nature of radioactivity and that atoms are the building blocks of all matter.
P.12.A.9 - Students know the number of electrons in an atom determines whether the atom is electrically neutral or an ion. Able to calculate the number of protons and electrons to determine the electric charge of an atom or ion.