A pure radio-chemical preparation was observed to disintegrate at the rate of 2140 counts/minutes at 12.35 P.M. of the same day, the disintegration rate of the sample was only 535 count/minutes. What is the half-life of the material?

A pure radio-chemical preparation was observed to disintegrate at the rate of 2140 counts/minutes at 12.35 P.M. . At 3.55 P.M. of the same day, the disintegration rate of the sample was only 535 count/minutes. What is the half-life of the material? a) 50 min b) 100 min c) 200 min d) None of these

A counter gives a count of 320 counts/minute for a radioactive source . After 75 minutes, the counter shows a count rate of 40 counts/minute . What is the half life period of the source ?

A sample contanining a radioactive isotope prduces 2000 counts per minutes in a Giege counter. Afte 120hours, the sample produces 250 counts per minutes. What is the half-life of the isotope?

(7)/(8)th of nuclei have been disintegrated in 2 minutes after fresh sample was prepared. The half life of the sample is

(7)/(8)th of nuclei have been disintegrated in 2 minutes after fresh sample was prepared. The half life of the sample is

A count rate meter shows a count of 240 per minute from a given radioactive source. One hour later the meter shows a count rate of 30 per minute. The half-life of the source is.

A count rate meter shows a count of 240 per minute from a given radioactive source. One hour later the meter shows a count rate of 30 per minute. The half-life of the source is

A count rate meter shows a count of 240 per minute from a given radioactive source. One hour later the meter shows a count the rate of 30 per minute. The half-life of the source is