the mass nos. of 3 isotopees of an element are 10, 12, and 14 units . Their percentage abundance is 80, 15 and 5 respectively. what is the atomic weight of the element?


i literally have no idea what to do here, i thought atomic mass and weight were the same thing????sad

rosala  Aug 2, 2017

3+0 Answers


Hi Rosala,


Calculate this by taking the weighted average


(80×10+15×12+5×14) / (80+15+5) = 10.5u


This is very close to Boron 10.8


This should be helpful in understanding.





GingerAle  Aug 2, 2017
edited by GingerAle  Aug 2, 2017

what does percentage abundance mean?


and basically what did you do?


check out this boy's answer, he used some other way, im sorta confused?


and he even changed the value of the percentages, idk whats happening?

rosala  Aug 2, 2017
edited by rosala  Aug 2, 2017

i got it, thanks gingerale, you are an inspiration to all the monkeys out there........they should get educated too....knowledge is power.......laugh

rosala  Aug 2, 2017

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