Question Library

A radioactive substance has a half-life of 20 hours. What fraction of the original radioactive nuclide will remain after 80 hours?

Which of the following are emitted from a radioactive substance without altering either the nucleon number or the proton number of the substance?

An element X of an atomic number 88 and mass number 226 decays to form an element Z by emitting two beta particles and an alpha particle. Z is represented by

An element whose half-life is 3 years has N atoms. How many atoms would have decayed after 9 years

When the nucleus of a uranium atom is split into two fragments of nearly equal mass the sum of the masses of the fragments is less than the mass of the original nucleus. This difference is a measure of the

After three half lifes, the fraction of a radioactive material that has decayed is

\(^{27}_{13}Al\) + \(^{1}_{0}n\) \(\Rightarrow\) \(^{24}_{11}Na\) + X

4g of a radioactive material of half-life 10 days is spilled on a laboratory floor. How long would it take to disintegrate 3.5g of the material?

Which of the following are True for \(\alpha\)-decay. i. mass number, decrease by four. ii. Atomic number decreases by two. iii. mass number does not change.

A radioactive substance has a half-life of 20 hours. What fraction of the original radioactive nuclei will remain after 80 hours?

Which of the following is not crystal?

The number of neutrons contained in the nucleus \(^{238}_{92}U\) is

Eight alpha decays and six beta decays are necessary before an atom of 2 \(^{238}_{92}U\) achieves stability. The final product in the chain has an atomic number of

Two radioactive elements A and B have half-lives of 100 and 50 years respectively. Samples of A and B initially contain equal amounts/number of atoms. What is the ratio of the number of the remaining atoms of A to that of B after 200 years?

A radioactive sample initially contains N atoms. After three half-lives the number of atoms that have disintegrated is