Question

PLEASE HELP!! Calculate the atomic mass of Mg if you know that 78.70% is ^24Mg. 10.13% is ^25Mg. 11.17% is ^26Mg.

Answer 1

this is another weighted average

Average mass = 0.7870*(mass of Mg 24) + 0.1013*(mass of Mg 25) + 0.1117*(mass of Mg 26)

Answer 2

so the answer would be the atomic mass of Mg??

Answer 3

well I don't know the masses of Mg 24, Mg 25, Mg 26

you need to look those values up in a table

Answer 4

then you use them to calculate the avg mass of Magnesium