Chromium has four naturally occuring isotopes. cr-50 (mass of 49.946 amu and 4.35% abundance); cr-52 (mass of 51.941 amu and 83.79% abundance); cr-53 (mass of 52.941 amu and 9.50% abundance); and cr-54 (mass of 53.939 amu and 2.36% adundance). calculate the average atomic mass of chromium.
51.996 amu
eliminate
b) 52.000 amu
c) 52.191 amu
d) 52.25 amu

B) 52.000 amu.

Explanation:

∴ Average atomic mass of Cr = (Cr-50 mass)(its abundance) + (Cr-52 mass)(its abundance) + (Cr-53 mass)(its abundance) + (Cr-54 mass)(its abundance)

Abundance of isotope = % of the isotope / 100.

∴ Average atomic mass of Cr = (49.946 amu)(0.0435) + (51.941 amu)(0.8379) + (52.941 amu)(0.095) + (53.939 amu)(0.0236) = 52.000 amu.

So, the right choice is: B) 52.000 amu.

the answer is d.) potassium