If the decay constant of a radioactive substance is 0.231s-\(^1\), the half-life is?
A piece of radioactive material contains 10\(^{20}\) atoms.
If the half life of the material is 20 seconds, the number of disintegration in the first second is?
Thermionic emission is the process whereby?
Which of the following can conduct electricity owing to the presence of free mobile electrons?
When a pentavalent impurity is added to a pure semiconductor, it becomes?
