Question

Chromium has four naturally occurring isotopes. Chromium-50 has a percent abundance of 4.35%, chromium-52 has a percent abundance of 83.79%, chromium-53 has a percent abundance of 9.50%, and chromium-54 has a percent abundance of 2.37%. Based on this information calculate the average atomic mass of chromium. *

Answer 1

Answer: The average atomic mass of chromium is 47.0

Step-by-step explanation:

Given,

Mass of isotope Cr - 50 = 50

% abundance of isotope Cr-50 = 4.35% =
`(4.35)/(100)=0.0435`

Mass of isotope Cr- 52 = 52

% abundance of isotope Cr-52 = 83.79 % =
`(83.79)/(100)=0.8379`

Mass of isotope Cr- 54 = 54

% abundance of isotope Cr-54 = 2.37 % =
`(2.37)/(100)=0.0237`

Formula used for average atomic mass of an element :

`\text{ Average atomic mass of an element}=\sum(\text{atomic mass of an isotopes}* {{\text { fractional abundance}})`

`Z=[(50* 0.0435)+(52* 0.8379)+(54* 0.0237)]`

`Z=47.0`

The average atomic mass of chromium is 47.0