A certain element x has four isotopes. 94.93% of x has a mass of 31.97207 amu. 0.7640% of x has a mass of 32.97146 amu. 4.290% of x has a mass of 33.96786 amu. 1.600*10-2% of x has a mass of 35.96709 amu. what is the average atomic mass of element x?

Average atomic mass is the weighted average atomic mass of an element with regard to the abundance of all its isotopes.

average atomic mass of X can be calculates as follows;

average atomic mass of X = sum of the products of mass of isotopes by their abundance percentages

average atomic mass of X = (94.93 % x 31.97207 amu) + (0.7640% x 32.97146 amu) + (4.290% x 33.96786 amu) + (1.600*10-2% x 35.96709 amu)

average atomic mass of X = 30.35 + 0.2519 + 1.457 + 0.005755

therefore average atomic mass of X = 32.06