URGENT!!! PLEASE HELP Europium has two naturally-occurring isotopes: europium-151 with an abundance of 47.82% and europium-153 with an abundance of 52.18%. Determine the average atomic mass for europium.

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 aqueous solution of ki freezes at the lowest temperature? 1) 1 mol of ki in 500. g of water 2) 2 mol of ki in 500. g of water 3) 1 mol of ki in 1000. g of water 4) 2 mol of ki in 1000. g of water

The density of benzene at 15 °c is 0.8787 g/ml. calculate the mass of 0.1500 l of benzene at this temperature. enter your answer in terms of grams