Questions in nuclei

Select	Question
	During mean life of a radioactive element, the fraction that disintegrates is
	1 Curie is equal to
	In the given nuclear reaction, how many $\alpha$ and $\beta$ particles are emitted $_{92}{X^{235}} \to {\;_{82}}{Y^{207}}$
	The electron emitted in beta radiation originates from
	When a radioactive substance emits an ?-particle, its position in the periodic table is lowered by
	During negative $\beta$ -decay
	Half-life is measured by
	A radioactive nucleus emits a beta particle. The parent and daughter nuclei are
	If a radioactive substance reduces to $\frac{1}{{16}}$ of its original mass in 40 days, what is its half-life
	In which of the following decay, the element does not change