Question

An unknown element X has the following isotopes: ¹ºX (20.00%-

abundant, atomic mass = 10.01 amu) and ¹¹X (80.00% abundant,
atomic mass = 10.99 amu). What is the average atomic mass in amu
of X?

Answer 1

asnwered by albert einstien

Step-by-step explanation:

The average atomic mass of an element is calculated by taking into account the relative abundances and atomic masses of all of its isotopes. To calculate the average atomic mass of element X, you can use the following formula:

Average atomic mass = (abundance of ¹ºX * atomic mass of ¹ºX) + (abundance of ¹¹X * atomic mass of ¹¹X)

Plugging in the values given in the problem, we get:

Average atomic mass = (0.20 * 10.01 amu) + (0.80 * 10.99 amu)

= 2.002 amu + 8.792 amu

= 10.794 amu

Therefore, the average atomic mass of element X is approximately 10.794 amu.

Note: It is important to express the abundances as fractions or decimals, not percentages, when performing this calculation.