##1xx10^22″atoms C”## are in a 1.00 carat diamond.

Convert 200 mg to g.

##”1000 mg=1 g”##

##200cancel”mg”xx(1″g”)/(1000cancel”mg”)=”0.2 g”##

Convert carats to grams to moles.

##”1.00 ct=0.2 g”##
##1″mol C=12.0107 g C”##

##1.00cancel”ct C”xx(0.2cancel”g C”)/(1cancel”ct C”)xx(1″mol C”)/(12.0107cancel”g C”)=”0.02 mol C”##

Convert moles C to atoms C.

##1 “mol C”=6.022xx10^23 “atoms C”##

##0.02cancel”mol C”xx(6.022xx10^23″atoms C”)/(1cancel”mol C”)=1xx10^22″ atoms C”## (rounded to one significant figure)