An element consists of 5.85% of an isotope with mass 53.940 u, 91.75% of an isotope with mass 55.9349 u, 2.12% of an isotope with mass 56.9354 u, and 0.28% of an isotope with mass 57.9333 u. calculate the average atomic mass, and identify the element.

Iknow the answer is a but i don't know why

The msds for glacial acetic acid says that it is a flammable liquid that can severely burn any human tissue it comes in contact with. it reacts with bases, various metals, and strong oxidizing agents. its vapors can form explosive mixtures with air.

Island arcsisland arcs are long, curved chains of oceanic islands associated with seismic activity and mountain-building processes at certain plate boundaries. they occur where oceanic tectonic plates collide. along one side of these island arcs, there is usually a long, narrow deep-sea trench. at island arcs, the denser plate is subducted and is forced into the partially molten mantle under the less dense plate. the islands are composed of the extrusive igneous rocks basalt and andesite. the basalt originates most likely from the plastic mantle. the andesite originates most likely from the melting of parts of the descending plate and sediments that had accumulated on its surface. which list identifies minerals present in andesite from the greatest percentage by volume to the least percentage by volume? a) biotite, plagioclase feldspar, amphiboleb) biotite, amphibole, plagioclase feldsparc) plagioclase feldspar, biotite, amphiboled) plagioclase feldspar, amphibole, biotite