Question

Calculate the atomic mass of chromium it’s composition is 83.79% with a mass of 51.94 amu; 9.50% with a mass of 52.94 Amu; 4.35% with a mass of 49.95 amu; 2.36% with a mass of 53.94 amu

Answer 1

Convert the percentages into decimals (you can do that by dividing the percent by 100), then multiply that by its corresponding mass to find its relative amount/ contribution to the atomic mass of chromium. After doing so, add all of the obtained values together to get the average mass.

83.79% = .08379
9.50% = .095
4.35% = .0435
2.36% = .0236

Average mass of chromium = 0.8379(51.94) + 0.095( 52.94) + 0.0435(49.95) + 0.0236(53.94)

Answer: 52amu

P.S. never forget units