An element X have three isotopes X ^20 ,X ^21 and X ^22 . The percentage abundance of X^20 is 90% and the average atomic mass of element is 20.18. The percentage abundance of X ^21 should be

 Answer Key: 2%

Calculate Average atomic mass of Argon the natural abundance % of isotopes of Argon is given as:

Answer Key: 39.94 amu

Calculate the average atomic mass of silicon if relative abundance is 92.23 ,isotope Si^28, 4.77 % isotope = Si^29 and 3% isotope = Si^39 .

Answer Key: The average atomic mass of silicon is 28.1 amu