Question

A soft silvery metal has two naturally occurring isotopes: mass 84.9118, accounting for 72.15% and mass 86.9092, accounting for 27.85%. The atomic weight of this metal would be:

Answer 1

Answer: The atomic weight of the metal would be 85.47.

Step-by-step explanation:

Mass of isotope 1 of metal = 84.9118

% abundance of isotope 1 of metal = 72.15% =
`(72.15)/(100)`

Mass of isotope 2 of metal= 86.9092

% abundance of isotope 2 of metal = 27.85% =
`(27.85)/(100)`

Formula used for average atomic mass of an element :

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

`A=\sum[(84.9118)* (72.15)/(100))+(86.9092)* (27.85)/(100)]]`

`A=85.47`

Therefore, the atomic weight of the metal would be 85.47.