A mixture of hydrogen and helium gases, at a total pressure of 844 mm Hg, contains 0.464 grams of hydrogen and 0.585 grams of helium. What is the partial pressure of each gas in the mixture

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.