The radioisotpe, N-13,has a half-life of 10.0 minutes is used to image organs in the body. If an injected sample has an activity of 40 microcuries `(40,muCi)`, what is its activity after 25 minutes in the body?

The radioisotpe, N-13,has a half-life of 10.0 minutes. What is the rate constant for the radioactive decay of N-13?

A radioactive sample has a half-life of 10 minutes. If 64 nuclei are contained in the sample the number of nuclei that would decay after 50 minutes is

A radioactive sample has an activity of 5.13xx10^(7)Ci . Express its activity in 'becqueral' and 'rutherford'.

A radioactive sample with half-life 2 days has initial activity 32mu Ci . What will be its activity after 8 days?

A radioactive nulei has half-life of 1.0 minute. If one of the nuclie decay now, the next nuclei will decay after:

Half life of ""^(131)I is 8 days. Sample has an activity 6.4 mCi at a certain time. What is the activity 40 days later?

(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.

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 ?