The term TYPE OF ATOM can be solved by two crossword solutions: ISOTOPE (7 letters) and ISOTONE (7 letters). An isotope is an atom that has a different number of neutrons than the standard atom, while an isotone is an atom with the same number of neutrons as the standard atom. Isotopes are used in various scientific fields, such as radiochemistry, geology, and medicine. Isotones are used in nuclear physics and chemistry.