Which of the following boxes contains isotones? (Numbers in the box represents mass number)
Isotopes - One of two or more atoms having the same atomic number but different mass numbers.
Cobalt=55, Cobalt=56, Cobalt=57 (each has 27 protons).
Isobar - Any of two or more kinds of atoms having the same atomic mass but a different atomic number.
Manganese-56, Iron-56, Cobalt-56
Isotones - One of two or more atoms whose nuclei have the same number of neutrons but different numbers of protons.
Manganese-56, Iron-57, Cobalt-58 (31 neutrons each).