Which is the primary ore of aluminium? Write its chemical formula.

Given below are the pictures of three types of metals and their ores. In each case identify the metal and write its name.

a)

b)

c)

Define the following terms:

Ores and minerals.

The froth floatation process is a process that is used industrially for the concentration of sulphide ores of various minerals. 

"If a metal has more than one mineral form, then it is not necessary that all of them are ores." Justify your statement.