Question

2. An element is a mixture of two isotopes. One isotope has an atomic mass of 34.969 amu and an

Answer 1

Answer:

0.3567

Explanation:

Answer 2

Answer: The average atomic mass of an element is 35.67 amu and the unknown element will be chlorine.

Explanation:

Mass of isotope 1 = 34.969 amu

% abundance of isotope 1 = 64.88% = $\frac{64.88}{100}=0.6488$

Mass of isotope 2 =  36.966 amu

% abundance of isotope 2 = (100-64.88)% = $\frac{100-64.88}{100}=0.3512$

Formula used for average atomic mass of an element :

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

$A=\sum[34.969\times 0.6488)+(36.966 \times 0.3512]]$

$A=35.67amu$

Therefore, the average atomic mass of an element is 35.67 amu and the unknown element will be chlorine.