Question

Magnesium has three naturally occurring isotopes (Mg-24, Mg-25, and Mg-26). Find the natural abundance and atomic mass of Mg-26.

a) Natural abundance: 79%, Atomic mass: 24.305 amu
b) Natural abundance: 10%, Atomic mass: 25.305 amu
c) Natural abundance: 11%, Atomic mass: 26.305 amu
d) Natural abundance: 10%, Atomic mass: 24.305 amu

Answer 1

The correct natural abundance and atomic mass of Mg-26 are 11% and 26.305 amu, respectively.

Step-by-step explanation:

The natural abundance and atomic mass of Magnesium-26 (Mg-26) is given by option c) which states a natural abundance of 11% and an atomic mass of 26.305 amu. This information is in agreement with data that indicates a sample of magnesium contains 11.17% of 26Mg atoms with a mass of 25.98 amu. Isotopes of magnesium, such as Mg-24, Mg-25, and Mg-26, are variants of the element that differ in the number of neutrons in their nuclei, while all containing 12 protons.