Which following statements is true? Electrons contribute most of the mass of an atom.
Electron placement determines an atom’s reactivity.
Proton location determines properties such as luster.
Neutrons determine whether an atom is liquid at room temperature.

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.