Definition of backpack. 1a : a load carried on the backb : a camping pack (as of canvas or nylon) supported by a usually aluminum frame and carried on the backc : knapsack.
Three types of radioation-Alpha, Beta, Gamma. There are three primary types of radiation: 1  Alpha-these are fast moving helium atoms. 2  They have high energy, typically in the MeV range, but due to their large mass, they are stopped by just a few inches of air, or a piece of paper.3  Beta-these are fast moving electrons. Alpha-these are fast moving helium atoms. 2  They have high energy, typically in the MeV range, but due to their large mass, they are stopped by just a few inches of air, or a piece of paper. 3  Beta-these are fast moving electrons. 4  They typically have energies in the range of a few hundred keV to several MeV.
Gamma rays and x-rays arenât the only kinds of ionizing radiation. Some types of ultraviolet (UV) radiation are also ionizing. Ionizing radiation can also exist in particle form, such as protons, neutrons, and alpha and beta particles.