In which state of matter are the particles the most spread out? ?

Gas is the state of matter with most spread out molecules because they can move around/are less compact, unlike solid or liquids.

The total number of nucleons

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).