In the three forms of radiation, why do Gamma Rays have higher penetrating abilities than Alpha particles and Beta

Question: In the three forms of radiation, why do Gamma Rays have higher penetrating abilities than Alpha particles and Beta particles?
- Keywords:
  alpha,
  beta,
  gamma,
  penetrating,
  penetration,
  radiating,
  radiation,
  ray
Asked by ninajepson to Daphne, Darren, Jon, Katherine on 21 Mar 2012.
- Daphne Ng answered on 21 Mar 2012:
  
  Gamma rays are very high frequency waves which are produced by radioactive decay whereas alpha and beta particles have lower frequencies. As a result, gamma rays have much higher energies as compared to alpha and beta particles. Hence, gamma rays have much higher penetrating abilities than alpha and beta particles. In fact, gamma rays can only be stopped with a lead shield of a few cm thick as compared to alpha and beta particles which can be stopped by paper and thin foil respectively.
- Katherine Haxton answered on 23 Mar 2012:
  
  Alpha particles are the nucleus of the helium atom, and really heavy compared to beta particles which are electrons. Alpha particles are quite easy to stop as Daphne says, beta particles take a bit more effort but gamma rays are very high energy electromagnetic radiation and hard to stop. It takes a lot of stuff to remove all the energy they have.

Question: In the three forms of radiation, why do Gamma Rays have higher penetrating abilities than Alpha particles and Beta particles?