State the S.I. unit of radioactivity.

Which of the following rays has the highest capacity to ionise gases? (a) α-ray (b) γ-ray (c) β-ray (d) Light ray

Which one among the radioactive rays is an electromagnetic wave?

What change will occur in atomic number if one β-particle is emitted from ²³⁵₉₂U?

Mention one practical application of controlled chain reaction. OR Why is a nuclear fission conducted before a nuclear fusion ?

By the emission of which radioactive ray from the atom of a radioactive element, no new atom is created?

Mention one peaceful use of atomic energy. OR Fill up the blank : γ-ray is ____ wave of short wavelength.

If the mass of an electron is m, then the mass of a β-particle is: (a) m (b) 2m (c) 3m (d) 4m

By which type of nuclear reaction is energy produced in a nuclear reactor?

Write the name of the positively charged radioactive particle.

Compare the charge, penetrating power and ionising power of α and γ rays.

The number of a and β particles emitted in the reaction 86A222 → 84B210 wouldrespectively be (a) 6α, 3β (b) 3α, 4β (c) 4α, 3β (d) 3α, 6β

The correct order of penetrating power of α-, β- and γ- rays is γ > α > β γ > β > α α > β > y β > γ > α