Question

How would you find the percent abundance of 2 isotopes of an element, given the atomic weight and mass number of each isotope?

Answer 1

. When two atoms of the same element have different numbers of neutrons and also have different masses. They are known as isotopes of that element. The difference in isotopes is due to the difference in the number of neutrons, the isotopes differ in their atomic weight, density, atomic volume, melting and boiling point.

Complete step by step answer:
- Isotopes generally occur naturally and so thus the percentage abundance of two isotopes can be calculated using the atomic mass and the average atomic masses. Atomic weight or atomic mass is the mass of an atom. The atomic mass is usually expressed in Dalton.
- The percentage abundance of isotopes of an element is determined using the given formula:
$a=\dfrac{b(x) + c(100 - x)}{100}$
Here, a = average atomic masses
b = atomic mass of one isotope
C= atomic mass of second isotope
And, x = percentage abundance of the first isotope

Note: The isotopes generally have the same physical and chemical properties and the atomic number of isotopes are also the same. This means that the isotopes have the same number of protons. The difference in isotopes is due to the difference in the number of neutrons, the isotopes differ in their atomic weight, density, atomic volume, melting and boiling point. On the other hand, if we talk about isobars, these are those elements which have the same mass number but different atomic number. Let’s take an example, argon and calcium both have the same mass number i.e. 20 but their atomic numbers are different i.e. 18 for argon and 20 for calcium.