What is the purpose of coefficients when balancing an equation?

Neils bohr believed that electrons orbited the nucleus in different energy levels, based on strong support from

An atom of lithium (li) and an atom of chlorine (cl) engage in a chemical reaction. which correctly describes the structure of the resulting chemical compound? hint: consider the class of each element. the chemical compound will have a network structure. the chemical compound will have triple bonds. the chemical compound will have a ball-and-stick structure. the chemical compound will have double bonds.

Can someone me with 3 and 4 plz. this is for masteries test.