The half-life of 238 92U undergoing α -decay is 4.5 × 109 years. What is the activity of 1g sample of 238 92U

The decay rate of a radioactive sample is called its activity. The half life of U_92^238 against alpha decay is 1.5x 10^17s . Calculate the activity of a sample of U_92^238 having 25 x 10^21 atoms.

On analysis a sample of Uranium was found to contain 0.2777 g of ""_(82)Pb^(206) and 1.667 g of ""(92)U^(238) . The half-life periodof ""_(92)^(238) is 4.51 xx 10^(9) years. If all the lead were assumed to have come from decay of ""_(92)^(238) , What is the age of the earth ?

A radioactive sample has a half- life of 1500 years. A sealed tube contains 1 g of the sample. How much quantity of sample will be left after 3000 years?

Spontaneous and continuous disintegration of a nucleus of a heavy element with the emissio of cer tain type os radiation is known as radioactivity. Tritium has a half-life of 12.5 years. What frac tion of a sample of pure tritium will remain undecayed after 50 years?

A small amount of solution containing a radioactive nucleide A was administered into blood of a patient. The activity of the nucleide is 2 xx 10^(3) dps. Its half life is 15 hours. After 5 hours a sample of the blood drawn out from the patient. It's activity was 16 dpm per mL. Radioactive nuclide A^(x) decays by beta^(-) emission (42%) beta^(+) emission (58%) in the patient body Then half value of beta^(-) decay path is