Question

A certain element exists as two different isotopes. 76.00% of its atoms have a mass of 35.00 amu and 24.00% of its atoms have a mass of 37.00 amu. What is the average atomic mass of this element? (Do not round your answer)
_________ amu
ANSWER ASAP PLEASE

Answer 1

Answer:

35.48 uma

Explanation:

An isotope is when an element has equal numbers of protons but different mass value because it has different amount of neutrons.

To calculate the average atomic mass with the given data:

First change de percentages to fractional numbers, divide by 100.

Remember the sum of a percentage is equal to 100, but when you are adding the fractions the sum is equal to 1.

76/100 = 0.76

24/100 = 0.24

  %       fraction

76.00 0.76

24.00 0.24

total100.00 1.00

Now, multiply the mass with their corresponding fraction:

35(0.76) = 26.60

37(0.24) =  8.88

%      fraction amu amu

76.00 0.76 35         26.60

24.00 0.24 37         8.88

total100.00 1.00    average 35.48

Now you add the calculated mass to obtain the average atomic mass of the element.

And the value you will get is 35.48 amu.

I included an excel table so you can review it, I like to organize all the given data and the calculation in tables, also I think is easier to understand.

Download xlsx