In the compound silver oxide (Ag₂O), for each one oxygen ion there are two silver ions. If oxygen forms ions with a -2 charge, what charge must each silver ion have?

It is a mixture. simply put, a compound must be pure, that is, of only one chemical structure and composition. a mixture is made of different chemical substances (i.e. elements, molecules, compounds) that are not chemically bonded to each other, but instead physically grouped together, as in the case of gasoline (a homogeneous solution).

Naoh + hbr -> nabr (salt) + h2o ca (oh)2 + 2hbr - - - > ca (br)2 + 2h2o

C, small, hard spheres with insignificant volumes

The answer to this question is a