Definition that contains atomic number
- isotope one of two or more atoms with the same atomic number but with different numbers of neutrons
- transuranic element any element having an atomic number greater than 92 (which is the atomic number of uranium); all are radioactive
- lanthanon any element of the lanthanide series (atomic numbers 57 through 71)
- actinide series (chemistry) a series of 15 radioactive elements with increasing atomic numbers from actinium to lawrencium
- rutherford atom first modern concept of atomic structure; all of the positive charge and most of the mass of the atom are contained in a compact nucleus; a number of electrons (equal to the atomic number) occupy the rest of the volume of the atom and neutralize the positive charge
- transuranic having an atomic number greater than 92
- magic number the atomic number of an extra stable strongly bound atomic nucleus: 2, 8, 20, 28, 50, 82 or 126
- periodic table (chemistry) a tabular arrangement of the chemical elements according to atomic number as based on the periodic law
- actinon any of a series of radioactive elements with atomic numbers 89 through 103
- transactinide any of the artificially produced elements with atomic numbers greater than 103