Atoms and Nucle...

The nuclide ¹³¹I is radioactive, with a half-life of 8.04 days. At noon on January 1, the activity of a certain sample is 600Bq. activity at noon on January 24 will be

U²³⁸ decays into Th²³⁴ by the emission of an α– particle. There follows a chain of further radioactive decays, either by α– decay or by β – decay. Eventually a stable nuclide is reached and after that, no further radioactive decay is possible. Which of the following stable nuclides is the end product of the U²³⁸ radioactive decay chain

If the mass of a radioactive sample is doubled, theactivity of the sample and the disintegration constant of the sample are respectively

Consider an initially pure `M\' g sample of ^AX, an isotope that has a half life of T hour. What is it\'s initial decay rate (N_A = Avagadro No)?

At a given instant there are 25% undecayed radioactive nuclei. After 10 s the number of undecayed nuclei reduces to 6.25%, the mean life of the nuclei is

Highly energetic electrons are bombarded on a target of an element containing 30 neutrons. The ratio of radii of nucleus to that of Helium nucleus is 14^1/3. The atomic number of nucleus will be

The ratio of ionization energy of Bohr\'s hydrogen atom and Bohr\'s hydrogen like lithium atom is

The fission of ²³⁵U can be triggered by the absorption of slow neutrons by a nucleus. Similarly a slow proton can also be used. This statements is

Consider a hypothetical annihilation of a stationary electron with a stationary positron. What is the wavelength of resulting radiation
(h = Planck\'s constant, c = speed of light, m₀ = rest mass)