Question

calculate atomic weight of silver which has two isotopes with the following properties : silver-107 (106.91 amu, 51.84% natural occurence) and silver-109 (108.90 amu, 48.16% natural occurence). please help

Answer 1

Answer: The atomic weight of silver is 107.87 amu

Explanation:

Mass of isotope silver-107  = 106.91 amu

% abundance of isotope silver -107 = 51.84% = $\frac{51.84}{100}=0.5184$

Mass of isotope silver-109 = 108.90 amu

% abundance of isotope silver-109  = 48.16% = $\frac{48.16}{100}=0.4816$

Formula used for average atomic mass of an element :

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

$A=\sum[(106.91\times 0.5184)+(108.90\times 0.4816)]$

$A=107.87amu$

Thus atomic weight of silver is 107.87 amu