Questions in nuclei

Select	Question
	If 20 gm of a radioactive substance due to radioactive decay reduces to 10 gm in 4 minutes, then in what time 80 gm of the same substance will reduce to 10 gm
	16 gm sample of a radioactive element is taken from Bombay to Delhi in 2 hour and it was found that 1 gm of the element remained (undisintegrated). Half life of the element is
	Unit of radioactivity is Rutherford. Its value is
	In which radioactive disintegration, neutron dissociates into proton and electron
	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
	What is the respective number of $\gamma$and $\gamma$ particles emitted in the following radioactive decay $_{90}{X^{200}}{ \to _{80}}{Y^{168}}$
	A radioactive reaction is$_{92}{U^{238}}{ \to _{82}}P{b^{206}}$. How many $\gamma$ and $\gamma$ particles are emitted
	A radioactive substance has a half life of 60 minutes. After 3 hours, the fraction of atom that have decayed would be
	A element used for radioactive carbon dating for more than 5600 years is
	After two hours, one- sixteenth of the starting amount of a certain radioactive isotope remained undecayed. The half life of the isotope is