Question

the atomic masses of chlorine - 35 (75.780 %) and chlorine - 37 (24.220 %) are 34.969 amu and 36.966 amu, respectively. calculate the average atomic mass of chlorine. the percentages in parentheses denote the relative abundances. (write the mass to correct significant figures followed by amu : example 1.23 amu)

Explanation:

Step1: Multiply mass by abundance for Cl - 35

$34.969\times0.75780$

Step2: Multiply mass by abundance for Cl - 37

$36.966\times0.24220$

Step3: Sum the results

$34.969\times0.75780 + 36.966\times0.24220=35.45$

Answer:

35.45 amu