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

Explanation:

Given,

Mass of isotope Cr - 50 = 50

% abundance of isotope Cr-50 = 4.35% = $\frac{4.35}{100}=0.0435$

Mass of isotope Cr- 52 = 52

% abundance of isotope Cr-52  = 83.79 % = $\frac{83.79}{100}=0.8379$

Mass of isotope Cr- 54 = 54

% abundance of isotope Cr-54  = 2.37 % =  $\frac{2.37}{100}=0.0237$

Formula used for average atomic mass of an element :

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

$Z=[(50\times 0.0435)+(52\times 0.8379)+(54\times 0.0237)]$

$Z=47.0$

The average atomic mass of chromium is 47.0