History

• Radon was the third radioactive element to ever be discovered. It was found by Friedrich Ernst Dorn in 1900 when he observed gas emanating from radium. In 1901, he discovered that it was radioactive. In 1910, radon was finally isolated, and the density was noted by Sir William Ramsay and Robert Whytlaw-Gray. It was not until 1984 that radon gas was found to be dangerous in homes and other buildings. Since then, extensive research into radon's effect on health has been made, and it has been found to be a leading cause of lung cancer.
  
  

Types

• The various types of radon are known as isotopes, which are varied versions of the gas with different atomic masses. None of these isotopes are stable, which makes them difficult to work with in laboratory settings. In total, there are 34 radioactive isotopes of radon. These isotopes all have varied half-lives and differ from each other because of the amount and types of radiation they emit. In most isotopes, alpha radiation is emitted.
  
  

Warning

• Radon is a naturally occurring gas that comes from uranium, which may be present in rocks that lie underneath buildings and homes. Because it cannot be seen or smelled, it is often present in homes and, after a while, can build up to dangerous amounts. Breathing in radon can cause lung cancer, and is known to be the second most abundant cause of the cancer and the sixth most abundant cause of cancer in general. It is important to check homes for radon using devices made especially for the job in order to make sure you are not breathing in the deadly gas.
  
  

Features

• The outer shell of an atom can contain up to eight electrons. Radon is one of the elements that have a full outer shell, making it a zero-valence element. This means that it is a very stable element, because it is not looking to pick up, get rid of, or share electrons with other elements. However, despite its low electronegativity, it is still more reactive than some of the other noble gases. Radon is also a highly radioactive element, making it difficult to combine with other elements to create compounds.
  
  

Function

• Despite being a dangerous radioactive gas, radon is used in some medical practices. The decay of radium chloride is used to actually treat cancer, and radon was also used at one time in X-rays. In alternative medicine, exposure to low amounts of radon, usually that which is present in natural hot springs, is supposed to ease pain caused by ailments such as arthritis. Because radon has a higher presence in the ground over fault lines, scientists can also use the gas to help map them out.