Question

Use the information for the isotopes of X to calculate the average atomic mass of X, and identify the element.
HELP. I don't remember learning this and my teacher said it'll be on my final exam.

Answer 1

each isotope contributes a portion of its weight to the average, but it's not a straight average. It's a \(weighted\) average. The total average mass will be equal to the sum of the \(percentages\) of each weight

Answer 2

the general equation will look like this:\[avg.weight = (weight \space of \space X)*(fraction \space of \space X) + (weight \space of \space Y)*(fraction \space of \space Y)\]

Answer 3

to turn the percentages into fractions, divide by 100 to get rid of the percent, so 6.5% as a fraction is 0.065