A naturally occurring sample of lithium contains 7.42% of 6 Li and 92.58% of 7 Li. The relative atomic mass of 6 Li is 6.015 and that of 7 Li is 7.016. Calculate the atomic mass of a naturally occurring sample of lithium.

Question

Philoid · Accepted Answer

Percentage composition of ⁶Li = 7.42%

Relative atomic mass of ⁶Li = 6.015

Percentage composition of the ⁷Li = 98.58%

Relative atomic mass = 7.016

Atomic mass = (percentage isotopic composition × relative mass of ⁶Li) + (percentage isotopic composition × relative mass of ⁷Li)

Atomic mass = (0.0742 × 6.015) + (0.9258 × 7.016)

= 0.446 + 6.49

= 6.936u

A naturally occurring sample of lithium contains 7.42% of 6Li and 92.58% of 7Li. The relative atomic mass of 6Li is 6.015 and that of 7Li is 7.016. Calculate the atomic mass of a naturally occurring sample of lithium.

A naturally occurring sample of lithium contains 7.42% of ⁶Li and 92.58% of ⁷Li. The relative atomic mass of ⁶Li is 6.015 and that of ⁷Li is 7.016. Calculate the atomic mass of a naturally occurring sample of lithium.