It is neither, it is a pure substance.
I think the answer is it represent the shape of orbitals that electrons can occupy within an atom.
Conduction
In metals, the electrons of each atom are delocalized, which means they are free to move about in the structure of the metal. When heat is applied at one end of the metal, the electrons there are excited and collide with surrounding particles, transferring their energy to them. This is what makes metals very good conductors of both heat and electricity.
2AgNO3 + Zn --> Zn(NO3)2 + 2Ag
Its a redox reaction, Zn is oxidised (0 --> 2+), Ag is reduced (1+ --> 0)
I believe the answer is background radiatin