What is the atomic mass of $^{6} L i$ $""^6Li$ , if the atomic mass of lithium is 6.941 amu, and $^{7} L i$ $""^7Li$ is 92.58% abundant and weighs 7.015 amu?

Question

What is the atomic mass of $^{6} L i$ $""^6Li$ , if the atomic mass of lithium is 6.941 amu, and $^{7} L i$ $""^7Li$ is 92.58% abundant and weighs 7.015 amu?

1 Answer

Impact of this question

13374 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-12-17T16:43:05

${Mass of}^{6} L i isotope = \frac{0.446 \cdot amu}{0.0742} = 6.011 \cdot amu$ $"Mass of "^6Li" isotope"=(0.446*"amu")/(0.0742)=6.011*"amu"$

Explanation:

The quoted atomic mass is the weighted average of the individual isotopic masses of $^{7} L i$ $""^7Li$ and $^{6} L i$ $""^6Li$ .

$6.941$ $6.941$ $amu$ $"amu"$ $=$ $=$ $7.015 \cdot amu \times 92.58 % + ({mass of}^{6} L i isotope) \times 7.42 %$ $7.015*"amu"xx92.58%+("mass of "^6Li" isotope")xx7.42%$

And thus, $6.495 amu + ({mass of}^{6} L i isotope) \times 7.42 % = 6.941 \cdot amu$ $"6.495 amu"+("mass of "^6Li" isotope")xx7.42%=6.941*"amu"$

And thus,

$({mass of}^{6} L i isotope) \times 7.42 % = (6.941 - 6.495) \cdot amu$ $("mass of "^6Li" isotope")xx7.42%=(6.941-6.495)*"amu"$

$({mass of}^{6} L i isotope) \times 7.42 % = 0.446 \cdot amu$ $("mass of "^6Li" isotope")xx7.42%=0.446*"amu"$

${mass of}^{6} L i isotope = \frac{0.446 \cdot amu}{0.0742} = 6.011 \cdot amu$ $"mass of "^6Li" isotope"=(0.446*"amu")/(0.0742)=6.011*"amu"$ .

How did I know that $^{6} L i$ $""^6Li$ had an abundance of $7.42 %$ $7.42%$ ?

Science

Math

Humanities

... and beyond

What is the atomic mass of $^{6} L i$ $""^6Li$ , if the atomic mass of lithium is 6.941 amu, and $^{7} L i$ $""^7Li$ is 92.58% abundant and weighs 7.015 amu?

1 Answer

Explanation:

Related questions

Impact of this question

Science

Math

Humanities

... and beyond

What is the atomic mass of 6Li""^6Li, if the atomic mass of lithium is 6.941 amu, and 7Li""^7Li is 92.58% abundant and weighs 7.015 amu?

1 Answer

Explanation:

Related questions

Impact of this question

What is the atomic mass of $^{6} L i$ $""^6Li$ , if the atomic mass of lithium is 6.941 amu, and $^{7} L i$ $""^7Li$ is 92.58% abundant and weighs 7.015 amu?