Now when it comes to the characteristics of beta particles, we can compare them to alpha particles. Here we can say the beta particles are much smaller than alpha particles. That's because an alpha particle is basically a helium-4 isotope, pretty large. We have two protons and two neutrons, whereas a beta particle is only an electron, incredibly small.

Now here we'd say that they're going to have lower ionizing power if an alpha particle were to get inside of biological tissue, since it's so large, it'll move much more slowly, giving it time to ionize all surrounding tissue. Beta particles, being electrons, move very rapidly, so they go through the material much quicker, not giving themselves ample time to ionize all biological tissue. And as a result of this, because they're so much smaller, because they can move faster, we can say that beta particles have a higher penetrating power.

If we continue looking at this chart down below, we're going to say we have our alpha decay of platinum-171 that gave us osmium-167. For beta decay, we have selenium-81 becoming bromine-81. In terms of size, alpha particles are the largest because they're represented by the helium-4 isotope. For beta particles, they're going to be smaller.

In comparison, ionizing power of alpha particles is the highest. We're going to say here that in comparison, beta particles have lower ionizing power. Since alpha particles are the largest, they have very slow penetrating power. We're going to say here that beta particles in comparison are higher.

Now what can shield us if the penetrating power is higher for beta particles? Well, here we need much more dense material, so like a sheet of metal or a thick chunk of wood. OK, so we need more dense material to stop the progression of a beta particle. So just remember we can compare these two to one another. Remember, size of them can contribute a lot to our ideas of ionizing power and penetrating power.