19.The Alkali and Alkaline Earth metals belong to which columns, respectively?
1 answer:
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Answer:- 23.0 mg
Solution:- Radioactive decay obeys first order kinetics and the first order kinetics equation is:
where, is the initial amount of radioactive substance and N is it's amount after time t. k is the decay constant.
From given information, Original amount, of the radioactive substance is 184 mg and we are asked to calculate the amount N after 15 days. It means, t = 15 days
Half life is given as 5 days. From the half life, we could calculate the decay constant k using the equation:
where, is the symbol for half life. let's plug in the value of half like to calculate k:
Let's plug in the values in the first order kinetics equation and solve it for N:
lnN = 3.136
N = 23.0 mg
So, 23.0 mg of Bi-210 would be remaining after 15 days.