A fictitious element X is composed of 10.0 percent of the isotope 55^X , 20.0 percent of the isotope 56^X , and 70.0 percent of the isotope 57^X . Calculate the weighted atomic mass of element X to the nearest tenth.

6 answers

To calculate the weighted atomic mass, you would use the percentages of the isotopes. Since the isotope is 55, its weight is 55. Since they are present in different amounts, you cannot just take the average, you have to do a weighted average using the percentages given.

So, the weighted atomic mass would equal (.10)(55)+(.20)(56)+(.70)(57)
5.5+11.2+39.9=56.6... Is that correct?
Yes that is what I arrived at as well.
Okay, thank you very much.
Wow, THANKS!
Since it's 56.6, then the element in question should be Nickel (Ni). Hope I'm right