Uranium- `238` decays to thorium-`234` with half-life `5xx10^(9) yr`. The resulting nucleus is in the excited state and hence further emits `gamma`-rays to come to the ground state. It emits `20 gamma`-rays per second. The emission rate will drop to `5 gamma`-rays per second in

^57Co decays to ^57Fe by beta^+ -emission.The resulting ^57Fe is in its excited state and comes to the ground state by emitting gamma -rays.The half-life of beta^+ -decay is 270 days and that of the gamma -emission is 10^(-8) s.A sample of ^57Co given 5.0xx10^9 gamma rays per second.How much time will elapse before the emission rate of gamma rays drops to 2.5xx10^9 per second ?

Co^57 decays to Fe^57 by beta^+ -emission.The resulting Fe^57 is in its excited state and comes to the ground state by emitting gamma -rays.The half-life of beta^+ -decay is 270 days and that of the gamma -emission is 10^(-8) s.A sample of Co^57 given 5.0xx10^9 gamma rays per second.How much time will elapse before the emission rate of gamma rays drops to 2.5xx10^9 per second ?

Assertion:When a nucleus is in an excited state, it can make a transition to a lower energy state by the emission of gamma rays . Reason:These are energy levels for a nucleus just like there are energy levels in atoms .

The isotopes ^57Co decays by electrons capture to "^57Fe with a half - life pf 272d. The "^57Fe nucleus is produced in an excited state, and it almost instantaneously emits gamma rays. What will be the activity after one year?

The isotopes "^57Co decays by electrons capture to "^57Fe with a half - life pf 272d. The "^57Fe nucleus is produced in an excited state, and it almost instantaneously emits gamma rays: Find the mean lifetime and decay constant for ''_Co^58

The isotopes "_Co^57 decays by electrons capture to "^57Fe with a half - life 272d. The "^57Fe nucleus is produced in an excited state, and it almost instantaneously emits gamma rays. If the activity of a radiation source "^57Co is 2.0 muCi now, how many "_Co^57 nuclei does the sorce contains?

.^(12)N beta decays to an excited state of .^(12)C , which subsequenctly decays to the ground state with the emission of a 4.43 -MeV gamma ray. What is the maximum kinetic energy of the emitted beta particle?

.^(12)N beta decays to an ecited state of .^(12)C , which subsequenctly decays to the ground state with the emission of a 4.43 -MeV gamma ray. What is the maxium kinetic energy of the emitted beta particle?