The nuclide `.^131 I` is radioactive, with a half-life of `8.04` days. At noon on January `1`, the activity of a certain sample is `60089`. The activity at noon on January `24` will be
A radioactive sample has a half-life of 20 years. The time at which the activity of the sample will reduce to 10% of its initial value is
A radio active sample with a half life of 1 month has activity 2 mu ci .Its activity 2 months earlier was
A radioactive sample with a half life of 1 month has the label : "Activity = 4 micro curie on 11-12-2013" . What will be activity after two months ?
A radioactive sample has a half-life of 4 years. Calculate the time in which the activity will be reduced to 25%.
A radioactive sample with a half-life of 1 month has the label : 'Activity= 2 microcurie on 1-8-1991'. What would be its avtivity two months earlier?
A radioactive sample with half-life 2 days has initial activity 32mu Ci . What will be its activity after 8 days?
The half-life of iodine-131 is 8.02 days. How long will it take for 80% of the sample to decay?
(a) A radioactive sample has 6.0 xx 10^(18) active nuclei at a certain instant. How many of these nuclei will still be the same active state after two half-lives? (b) Radioactive phosphours -32 has a half-life of 14 days. A source containing this isotope has an initial activity of 10muCi . (i) What is the activity of the source after 42 days? (ii) What time elapse before the activity of the source falls at 2.5muCi ? (c) 1g of a radioactive substance disintergrates at the rate of 3.7 xx 10^(10) dps . The atomis mass of the substance is 226 . Calculate its mean life.
