Question

The mass in grams of 2.75 x 1021atoms of Li is.

Answer 1

Hey there!

atomic mass Li = 6.941 a.m.u

6.941 g Li ------------------------ 6.02x10²³ atoms
grams Li ------------------------- 2.75x10²¹ atoms

grams Li =  (2.75x10²¹ ) * 6.941 / 6.02x10²³

grams Li = 1.908775x10²² / 6.02x10²²

grams Li = 0.0317 g