In the compound mgcl2, the subscript 2 indicates that
a. there are two magnesium ions for each ion of chlorine
b. the chloride ion is twice the size of the magnesium ion.
c. magnesium and chlorine form a double covalent bond.
d. there are two chloride ions for each magnesium ion.

Pegmatites are igneous rocks in which the individual minerals are very large. typically, the minerals are all light-colored quartz, feldspar and muscovite. if you were given a black and white photograph of a pegmatite in a quarry (where the rock has been blasted and broken), what physical properties could you use to identify those three minerals in this hypothetical photo? describe each mineral and the specific diagnostic properties. be specific.