The strategy here would be to convert mass to moles and then from moles to the number of atoms.
100.0 g of iron(iii) oxide, or Fe2O3, has a molar mass of 159.687 g/mol. To convert the mass into the number of moles, divide the mass by the molar mass: (100.0 g)(159.687) = 0.6262 moles Fe2O3.
1 mole of any substance is, by definition, equal to 6.022 • 10^23 units of that substance. So to compute the number atoms contained in 0.6262 moles of Fe2O3, multiply (0.6262)(6.022 • 10^23) = 3.771 • 10^23 atoms of iron(iii) oxide, which is your answer (given to four significant figures).
I think this is true because they’re in the same layer, strata which would mean they died around the same time. Hope this helps sorry if it’s wrong!
A plasma is a hot ionized gas consisting of approximately equal numbers of positively charged ions and negatively charged electrons. The characteristics of plasmas are significantly different from those of ordinary neutral gases so that plasmas are considered a distinct "fourth state of matter