Question

64%
The element thallium is 70% thallium-205 and 30% thallium-203. Calculate its relative atomic mass to 1 decimal place

Answer 1

Answer:

1)

availability of Tl-205 is 70%

2)

availability of Tl-203 is 30%

NOW,

we know,

$relative \: atomic \: mass \\ = \frac{a(1) \times m(1) + a(2) \times m(2)}{100} \\ = \frac{70 \times 205 + 30 \times 203}{100} \\ = \frac{14350 + 6090}{100} \\ = \frac{20440}{100} \\ = 204.4 \\ = 204 \: (approx)$