Arrange the following radiations in order of increasing ionization of air.
I. Alpha
Il. Gamma
IIl. Beta
I < III < II
II < I < III
II < III < I
I < II
Correct answer is C
Alpha particles are highly ionising because of their double positive charge, large mass (compared to a beta particle) and because they are relatively slow.
They can cause multiple ionisations within a very small distance.
And the gamma radiation has the least ionising power.