Penetrating power of the rays are

γ-rays and X-rays have high penetrating power and travel several tens to hundreds of meters in the air. Alpha particles can be blocked by a few pieces of paper. Beta particles pass through a paper but are stopped by aluminum foil. Gamma rays are most difficult to stop and require concrete, lead or other heavy shielding to block them.

Hence Order of penetrating power is $\mathrm{\gamma }>\mathrm{X}\text{-rays }>\mathrm{\beta }>\mathrm{\alpha }$