How many silicon 30 atoms are found in this plate?

The silicon in the plate is a mixture of naturally occurring isotopes. One of the those isotopes is silicon-30, which has an atomic mass of 29.97376 amu and a percent natural abundance of 3.10%. read more

Atoms of Silicon-30 The question tells us that 3.10% of silicon atoms are of the silicon-30 isotope. Assuming that this is also the case for our plate, the number of silicon-30 atoms will be: 3.10% * 3.154*10^21 "atoms" = 0.031 * 3.154*10^21 "atoms" = 9.778*10^19 "atoms" The least amount of significant figures in the question is 3, so our answer is going to have 3 significant figures: 9.78*10^19 "atoms". read more

Monel metal is a corrosion-resistant copper-nickel alloy used in the electronics industry. A particular alloy with a density of 8.80 g/cm^3 and containing 0.077 % Si by mass is used to make a rectangular plate that is 15.0 cm long, 12.5 cm wide, and 3.50 mm thick and has a 2.50-cm-diameter hole drilled through its center. read more