Volcanic molten lava pours out and re-hardens back into the rock again. Chemical change or physical change?

Which of the following are correct values for the ideal gas laws constant r

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.

Which statement best describes the he properties of iconic compounds ?