Assertion (A): Out of α, β and γ radiation, α-particles have maximum penetrating power.

Reason (R): The α-particles are the heaviest amongst the three.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true and R is not the correct explanation of A.
3. assertion is false but reason is true.
4. assertion is true but reason is false.

Assertion (A): ¹⁴₆C and ¹⁴₇N are isobars.

Reason (R): ¹⁴₆C has 6 protons and 8 neutrons in its nucleus, whereas ¹⁴₇N has 7 protons and 7 neutrons in its nucleus.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true and R is not the correct explanation of A.
3. assertion is false but reason is true.
4. assertion is true but reason is false.

Arrange the α, β and γ radiations in ascending order of their (i) ionizing power, and (ii) penetrating power.

State the speed of each of α, β and γ radiations.