Crossword clues for the word: ISOTONE The word ISOTONE has appeared as an answer to at least 5 crossword clues on different crossword puzzles. Crossword clues for ISOTONE Showing 1 to 5 of 5 results Clue(s) Either of two atoms with equal neutrons but not protons One of a group of atoms having the same number of neutrons but a different number of protons One of a related set of atoms One of two nuclides with the same neutron number but different proton numbers Type of atom