Problem: An element has two naturally occurring isotopes. Isotope 1 has a mass of 120.9038 amu and a relative abundance of 57.4%, and isotope 2 has a mass of 122.9042 amu.By comparison to the periodic table, identify this element.

🤓 Based on our data, we think this question is relevant for Professor Montag's class at COD.

FREE Expert Solution

We’re being asked to identify the element given the mass of its naturally occurring isotopes.


We can use the following equation:


Atomic mass = [mass ×f.a.]isotope 1 +[mass×f.a.]isotope 2


where atomic mass = average atomic mass of the element and f.a. = fractional abundance of the isotope

To get f.a., we simply need to divide the given percent abundance by 100.


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Problem Details

An element has two naturally occurring isotopes. Isotope 1 has a mass of 120.9038 amu and a relative abundance of 57.4%, and isotope 2 has a mass of 122.9042 amu.

By comparison to the periodic table, identify this element.

Frequently Asked Questions

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Isotopes concept. You can view video lessons to learn Isotopes. Or if you need more Isotopes practice, you can also practice Isotopes practice problems.

What professor is this problem relevant for?

Based on our data, we think this problem is relevant for Professor Montag's class at COD.