What are isotopes used for in chemistry

Bohr's model could only explain the spectra of which type of atoms? single atoms with one electron single atoms with more than one electron bonded atoms with one electron bonded atoms with more than one electron

Achange in the number of neutrons in an atom will change an blank . when the number of protons changes in an atom, a new element will form.

What are transitions between a liquid and a solid called? identify which way they are transitioning