The half-life of the radio element \[_{83}B{{i}^{210}}\] is 5 days. Starting with 20 g of this isotope, the amount remaining after 15 days is [BHU 1987]

The half-life of the radio element \[_{83}B{{i}^{210}}\] is 5 days.

1.	The half-life of the radio element \[_{83}B{{i}^{210}}\] is 5 days. Starting with 20 g of this isotope, the amount remaining after 15 days is [BHU 1987]
A.	10 g
B.	5 g
C.	2.5 g
D.	6.66 g
Answer» D. 6.66 g

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The half-life of the radio element \[_{83}B{{i}^{210}}\] is 5 days. Starting with 20 g of this isotope, the amount remaining after 15 days is [BHU 1987]

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