question_answer 23)

In a Periodic Table the average atomic mass of magnesium is given as 24.312 u. The average value is based on their relative natural abundance on Earth. The three isotopes and their masses are   and  (25.98259 u). The natural abundance of  is 78.99% by mass. Calculate the abundances of the other two isotopes.  

Answer:

Let the natural abundance of  is x%. Then natural abundance of  is (100-78-99)% 24-312 or or Natural abundance of  is 9-31% Also, natural abundance of  is (100