Last week, we had a special visitor on our class , Tom Vales. He introduced us to radioactivity. In radioactive processes, particles or electromagnetic radiation are emitted from the nucleus. The most common forms of radiation emitted, have been traditionally classified as alpha particle (α), beta particles (ß), and gamma rays (γ). Elements that are radioactive are unstable elements; therefore the particles in it will continue to decay until they have reach stability.All radioactive elements will eventually decay to lead. Alpha particles consists of two protons and neutrons; while beta particles are electrons. Gamma rays are the strongest of all and can penetrate more materials. The picture below shows a representation of how strong are there types of radiation:
Image 1: Penetration power of alpha particles, beta particles and gamma rays
The life expectancy of these radioactive particles is known as the half life; in other words, its the amount of time that it will take for a particle to decay and reach stability. Uranium- 238, a common element in radioactivity, has a half life or about 4 billion years. Tom, taught us that even though Uranium is today mainly used for nuclear reaction, in the past it had different purposes.
People believed hat uranium had healing properties and so radioactive pills where created; the ingestion of these was and still is dangerous. In general ingestion of Uranium is very dangerous. Other daily used objects contained uranium as well such as fiestaware; this was a set of plates that used uranium on their ingredients to give it different coloring. Pocket watches and light poles of the time , also had uranium on their component since this element will glow in the dark.
All of the elements that I just mentioned were presented to us in class by Tom; and in case we didn’t believe what he was saying, he also had a Geiger counter. A Geiger counter (see picture below) is a device that measures the radioactivity of an object. It will produce a tone if there is a radioactive element around; the more radioactive the object is the faster the tone will sound. A constant tone means a very radioactive element and therefore dangerous. With his own Geiger counter, Tom demonstrated that all the object that he has presented to us were radioactive. The levels of radioactivity that we were exposed were very low so we had no reason to worry about any side effects from this presentation.
Image 2 : Geiger Counter