Radioactivity

Out of the two characteristics – the mass number (A) and the atomic number (Z) – of a nucleus, which one does not change during nuclear  $\beta -$ decay?

Out of the two characteristics – the mass number (A) and the atomic number (Z) – of a nucleus, which one does not change during nuclear  $\beta -$ decay?

The end product on the $\beta -$ decay of  ${}_{15}^{32}P$  is:

The end product of the ${\mathrm{\beta }}^{-}$ decay of ${}_{15}^{32}\mathrm{P}$ is

Which are amongst the following represent plot of the distribution of kinetic energy of $\beta -$ particles?

$\beta -$particle is emitted in a radio active reaction when

Gamma rays travel at a speed less than the speed of light.

Speed of alpha particles is more than that of velocity of light.

How do you find the daughter nuclei in nuclear decay?

What is parent nuclei and daughter nuclei?

The positron is antiparticle of

What is antimatter?

Out of the two characteristics – the mass number (A) and the atomic number (Z) – of a nucleus, which one does not change during nuclear  $\beta -$ decay?

In a radioactive decay chain, the initial nucleus is ${ }_{90}^{232}\mathrm{Th}$. At the end, there are $6$ $\alpha$-particles and $4\beta$-particles which are emitted. If the end nucleus is ${}_{\mathrm{Z}}^{\mathrm{A}}\mathrm{X}, A$ and $Z$ are given by:

Penetrating power of Gamma radiation is very low.

Which of the following statements is/are correct?
i. $\alpha$ particles are photons.
ii. Penetrating power of $\gamma$ radiation is very low.
iii. Ionization power is maximum for α rays.
iv. Penetrating power of $\gamma$ radiation is very high.

Radioactivity was first discovered in which year?

Choose the SI unit of radioactivity.

Who discovered natural radioactivity?