How many moles are equal to #1.2 times 10^21# molecules of lithium?

1 Answer
Mar 19, 2017

Answer:

#1.2xx10^21color(white)(.)"atoms Li"=2.0xx10^(-3)color(white)(.)"mol Li"#.

Explanation:

Lithium is a metal. It does not exist as molecules. We can, however, determine the moles equal to #1.2xx10^21# atoms of lithium.

#"1 mol atoms"=6.022xx10^23# atoms

#1.2xx10^21color(red)cancel(color(black)("atoms Li"))xx(1"mol Li atoms")/(6.022xx10^23color(red)cancel(color(black)("atoms Li")))=2.0xx10^(-3)"mol Li"# (rounded to two significant figures)