What is enthalpy? O the heat given off during an exothermic reaction
O the heat absorbed or released during a phase change
o the heat content of a system at constant pressure
o the heat absorbed during an endothermic reaction

Smog is the term used to describe the combination of fog and smoke

The atomic number, or number, is the described as the number of in the nucleus of an chemical element.

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.