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.
In the universe there are kinds of energy and different ways it manifests itself. One common form is radiation. Radiation is the wave energy produced by electromagnetic forces. There are different kinds and their strength can be divided into three categories. There are alpha rays, beta rays, and finally gamma rays. Essentially each example is high energy particles traveling in a straight line.