Consider the newly discovered element Steppium. Analysis of the element revealed that the average mass was 35.45 amu and the presence of two isotopes. The isotopes had masses of 34.9689 and 36.9695 with the lighter isotope present in grater abundance. What are the percent abundances of the two isotopes of Steppium. Please provide an explanation :)

Island arcs island 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?