Which general trend is demonstrated by the group 17 elements as they are considered in order from top to bottom on the periodic table?
(1) a decrease in atomic radius
(2) a decrease in electronegativity
(3) an increase in first ionization energy
(4) an increase in nonmetallic behavior

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.