Which is the number of atoms in 4.5 moles of Hg, correctly written in scientific notation with the correct number of significant figures?
Avogadro's number
represents the number of units in one mole of any substance. This has the value
of 6.022 x 10^23 units / mole. This number can be used to convert the number of
atoms or molecules into number of moles.
4.5 moles ( 6.022x10^23 atoms / 1 mol ) = 2.7x10^24 atoms Hg.