A sample of a certain element contains

448

atoms of isotope

A

and

318

atoms of isotope

B

. Determine the % abundance of isotope A. Show work, give answer with 3 sig figs. and box your answer.\ Determine the number of atoms contained in

2.74\\\\times 10^(4)mmol

(millimoles) of an element. Clearly show work using dimensional analysis, give answer with correct sig. figs and box your answer.