What is the atomic mass of lithium if 7.42% of its atoms have the mass of 6.02amu and 92.58% of its atoms have the mass of 7.02amu?

1 Answer

Answer:

#"6.9458 amu"#

Explanation:

Consider 10000 atoms of #"Li"#.

#742 # of them would have mass #6.02#.
#9258# of them would have mass #7.02#.

Hence the total mass of these #"10000 Li"# atoms would be

#(742xx6.02)+(9258xx7.02)=69458#

#therefore# #"1 Li"# atom on average would have mass of #69458/10000="6.9458 amu"#.