A certain element X has four isotopes. 5.845% of X has a mass of 53.93961 amu. 91.75% of X has a mass of 55.93494 amu. 2.123% of X has a mass of 56.93539 amu. 0.2820% of X has a mass of 57.93328 amu. What is the average atomic mass of element X? Express your answer numerically to four significant figures.

Average atomic mass of element X is 56.19 amu

Explanation:

Given:

Four isotopes of X:

5.845% of X has a mass of 53.93961 amu.

91.75% of X has a mass of 55.93494 amu.

2.123% of X has a mass of 56.93539 amu.

0.2820% of X has a mass of 57.93328 amu.

To find: average atomic mass of element X

Solution:

Isotopes are variants of a particular chemical element such that they have the same number of protons but different number of neutrons.

Average atomic mass of element X =

So, the average atomic mass of element X is 56.19 amu.