Use the information for the isotopes of element X to calculate the average atomic mass of X, and identify the element.

Isotope Abundance Mass (amu)
35X 75.77% 34.969
37X 24.23% 36.965

please help, i dont understand how too this.

Question

Use the information for the isotopes of element X to calculate the average atomic mass of X, and identify the element.

Isotope  Abundance       Mass (amu) 
35X        75.77%             34.969 
37X        24.23%              36.965

please help, i dont understand how too this.

joannablackwelder · Answer

Average atomic mass is the sum of the contributions of each isotope where the contribution of an isotope = fractional abundance * mass of isotope.

anonymous · Answer

so what equation would i use to get the answer for this question?

joannablackwelder · Answer

Both

joannablackwelder · Answer

Find the contribution of each isotope and add them up.

anonymous · Answer

so 24.23%  *  36.965 + 75.77%  *  34.969  =  mass ?

joannablackwelder · Answer

Yup, just divide the percents by 100.

anonymous · Answer

Awesome!  ( i suck at chemistry ) thanks for the help :)

joannablackwelder · Answer

No worries. What element did you identify?

anonymous · Answer

chlorine
am i correct?

joannablackwelder · Answer

Sweet, me too. :)

anonymous · Answer

nice :)