Nature of γ-rays :

1. γ-rays are electromagnetic waves of very short wavelength (about 10^-12 m to 10^-14 m). 

2. They are uncharged.

Properties of γ-rays :

1. γ-rays produce feeble ionization. Their ionizing power is 104 times less than that of a-particles and 100 times less than that of β-particles.

2. They have the maximum penetrating power. It is about 100 times that of βparticles and 10⁴ times that of αparticles.

3. They are not deflected by electric and magnetic fields as they are uncharged.

4. They affect photographic plates.

5. They cause fluorescence in a fluorescent material such as zinc sulphide.

6. Their speed in free space is 3 × 108 m/s( the same as that of light waves and X-rays in free space).

7. γ-rays can be diffracted by crystals. In recent times, γ-ray diffraction has emerged as a powerful tool in structural and defect studies of crystals.

8. They destroy living cells and tissues and are used for destroying cancer cells.

[Note : γ-rays (not established clearly in Berquerel’s work) were discovered in 1900 by Paul Villard (1860-1934), French physicist.]