Describe the independent and dependent variables in this experiment then describe the other variables that need to be controlled

Find the number of grams of hcl needed to react completely with .50 moles of magnesium.

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.

I’m an electrically neutral atomic any element, there are equal numbers of