Atoms and Nucle...

16 g sample if a radioactive element is taken from Bombay to Delhi in 2 hour and it was found that 1 g of the element remained (undisintegrated). Half life of the element is

Unit of radioactivity is Rutherford. Its value is

The count rate of a Geiger-Muller counter for the radiation of a radioactive material of half life of 30 minutes decreases to 5 s^–1 after 2 hours. The initial count rate was

In a radioactive decay, the half-life of radioactive substance is t_1/2 = 69.3 sec. The decay constants is

An element used for radioactive carbon dating for more than 5600 years is

The radioactive nucleus ₇N¹³ decays to ₆C¹³ through the emission of

The counting rate observed from a radioactive source at t = 0 second was 1600 counts per second and at t = 8 seconds it was 100 counts per second. The counting rate observed, as counts per second at t = 6 seconds, will be

In a radioactive decay, neither the atomic number nor the mass number changes. Which of the following would be emitted in the decay process

The half life period of a radioactive substance is 5 min. The amount of substance decayed in 20 min will be

²²Ne nucleus after absorbing energy decays into two a - particles and an unknown nucleus. the unknown nucleus is