Radon is an element situated on number 86 of the periodic table, this also tells us the atomic number, The number of protons, neutrons and electrons. In this essay, I am going to tell you more about this element, how it is linked to three of the little big history thresholds, and of course, radon’s story even though it only dates back until the year 1900. But I’ll start with radon’s background before we go in deeper into detail on its story and linkage with the thresholds.Information about radonAs I said radon has atomic number 86, this means that radon consists of 86 protons and 86 electrons. The atomic mass of radon is 222 u, to get to this number, radon must consist of 136 neutrons + 86 protons = 222. The electrons have such a low mass that in chemistry they categorize the mass as 0, so the function of the electrons is only to make radon-86 a stable compound. A proton is a subatomic particle with a positive charge, a proton has a slightly lower mass than a neutron. Both are said to have a mass of 1 u. U means unified atomic mass unit. A neutron is a subatomic particle with no charge and is slightly heavier than a proton. Protons and neutrons constitute the nuclei of atoms. An electron is a negatively charged particle surrounding the atom in the electron cloud. The electrons must balance the protons out hence the number of electrons – 86=86.The symbol for radon is Rn, Rn is a colourless substance with a density of 9.73 g/cm3 at 0 ?. Radon is a noble gas, a noble gases is an element which is part of the group noble gases with similar chemical elements with similar properties; in normal conditions, they are all odourless, colourless. We have six noble gases which occur naturally, helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn) which is radioactive.Radon its historyRadon was the fifth element found in 1899 by Ernest Rutherford and Robert B. Owens. Next to Radon, they found uranium, thorium, radium and polonium. They detected a radioactive gas being released by thorium.Pierre and Marie Curie detected a radioactive gas emanating from radium. Friedrich Ernst Dorn a German chemist observed in 1900 that a gas was accumulating during the decay of radium. He too discovered Radon. Both found different isotopes of the element Radon, Ernest Rutherford found radon-220 and Friedrich Ernst Dorn found radon-222. If an element has an isotope, it means that there is another alternative version of the element with a different amount of neutrons. Radon has Thirty-seven radioactive isotopes, with atomic masses ranging from 193 to 229. None of them stable, only Radon-222. Friedrich Ernst Dorn observed that Radon-222 has a half-life of 3.8 days. Pierre and Marie Curie detected the same element as Friedrich Ernst Dorn.The radon that Rutherford detected was radon-220 with a half-life of 56 seconds. Ernest Rutherford and Robert B. Owens saw that radon was released by thorium. Thorium is a weakly radioactive metallic chemical element with symbol Th and atomic number 90. Threshold 8: The modern RevolutionThe period of the modern revolution started around 1700-1800, around that time we humans started discovering new elements. Thorium was found in 1828, if a further possible investigation would have been done, we could have seen that radon was already there. Because of the fact that one way of radon occurrence, through the decay of thorium, radon must have been around earlier. Thorium has a half-life of 14.05 billion years so it should have been around earlier. Thorium decays very slowly, so it is possible that radon was around before we were. But this threshold is about the modern time not about the past, so older homes are often built on a foundation made out of natural stones like granite, limestone and other quarry rocks, radon gas is created when certain rocks begin to decompose and erode. Granite is one such stone that has trace amounts of uranium. If your foundation is made up from natural stone it may contains granite, when granite decompose ,it can create radon what can enter your basement through the floor and cause some big problems . Water that has no natural movement for some time will become stagnant. When this happens, many biological organisms can grow and die in the stagnant water, this creates gases. When these gases begin to interact with the soil and rocks surrounding it, radon gas can be formed. This can create radon in basement environments, as it will begin to build to the point where it needs to escape. This escape is towards your basement floor into your house.