Brainiest to the first person to get it right

The difference between the atomic number of an element and the element’s atomic mass is the number of ions.

Write the chemical formula for a compound that is made of an element from group 1 and an element from group 17

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.