Question

A certain element has four stable isotopes. The first has a mass of 50.01 amu and an abundance of 8.00%. The second has a mass of 48.98 amu and an abundance of 32.6%. The third has a mass of 52.99 amu and has an abundance of 38.3%. The final has a mass of 51.98 amu and an abundance of 21.1%. Calculate the average atomic mass of the element.

a) 50.01 amu
b) 48.98 amu
c) 52.99 amu
d) Calculate the average atomic mass.

Answer 1

The average atomic mass of the element with four stable isotopes is calculated using the weighted average, resulting in 51.2484 amu.

Step-by-step explanation:

To calculate the average atomic mass of an element with multiple stable isotopes, you need to take into account the mass of each isotope and its relative abundance. The calculation is a weighted average, meaning that it reflects both the mass and the proportion of each isotope present in nature. For the element in question, the calculation would be:

• (50.01 amu × 0.08) + (48.98 amu × 0.326) + (52.99 amu × 0.383) + (51.98 amu × 0.211) =
• (4.0008 amu) + (15.9838 amu) + (20.2957 amu) + (10.9681 amu) =
• 51.2484 amu

So, the average atomic mass for this element is 51.2484 amu.