Xenon which is used commercially is extracted from liquid air by fractional distillation. Xenon was also discovered by Ramsay and Travers in The name is derived from the Greek word for "stranger," xenos. Xenon lights glow with a blue light, and also emits some low-frequency ultraviolet light. Xenon lights are used in tanning beds, biocidal lamps used in food preparation, car headlights, flash lighting on cameras, strobe lights used in high-speed photography, and has been tested for use in space travel in ion-propulsion engines such as the experimental NASA spacecraft Deep Space 1.
Radon is a colorless, odorless, radioactive gas which liquefies at It is found in the Earth's crust in only trace amounts, and is one of the ten least abundant elements; it is found in the atmosphere at a concentration of 10 -9 ppt by volume. Radon was discovered in by Friederich Ernst Dorn while investigating "radium emanation" first observed by Marie and Pierre Curie , a gas found in sealed vessels of radium.
The name is a variation on the name of the element radium. It is produced in the radioactive decay of uranium and thorium, which in a series of steps decay into radium, which then undergoes alpha-decay to produce radon. The most common isotopes of radon are radon and radon, which have half-lives of Although chemically unreactive, when radon is produced, it can escape from the ground in the gas form, and collect in basements, or other contained areas.
Radon is an alpha-particle emitter; while alpha particles can be blocked easily, if the radon gas is inhaled, and undergoes alpha decay in the lungs, it produces an isotope of polonium, which is a solid, as are all of its decay products, some of which have half-lives of over 20 years. John Emsley, The Elements , 3rd edition. Oxford: Clarendon Press, Oxford: Oxford University Press, David L. Atomic number The number of protons in an atom. Electron configuration The arrangements of electrons above the last closed shell noble gas.
Melting point The temperature at which the solid—liquid phase change occurs. Boiling point The temperature at which the liquid—gas phase change occurs. Sublimation The transition of a substance directly from the solid to the gas phase without passing through a liquid phase. Relative atomic mass The mass of an atom relative to that of carbon This is approximately the sum of the number of protons and neutrons in the nucleus. Where more than one isotope exists, the value given is the abundance weighted average.
Isotopes Atoms of the same element with different numbers of neutrons. CAS number The Chemical Abstracts Service registry number is a unique identifier of a particular chemical, designed to prevent confusion arising from different languages and naming systems.
Murray Robertson is the artist behind the images which make up Visual Elements. This is where the artist explains his interpretation of the element and the science behind the picture. Where the element is most commonly found in nature, and how it is sourced commercially. Atomic radius, non-bonded Half of the distance between two unbonded atoms of the same element when the electrostatic forces are balanced. These values were determined using several different methods.
Covalent radius Half of the distance between two atoms within a single covalent bond. Values are given for typical oxidation number and coordination. Electron affinity The energy released when an electron is added to the neutral atom and a negative ion is formed.
Electronegativity Pauling scale The tendency of an atom to attract electrons towards itself, expressed on a relative scale. First ionisation energy The minimum energy required to remove an electron from a neutral atom in its ground state.
The oxidation state of an atom is a measure of the degree of oxidation of an atom. It is defined as being the charge that an atom would have if all bonds were ionic. Uncombined elements have an oxidation state of 0. The sum of the oxidation states within a compound or ion must equal the overall charge. Data for this section been provided by the British Geological Survey. An integrated supply risk index from 1 very low risk to 10 very high risk. This is calculated by combining the scores for crustal abundance, reserve distribution, production concentration, substitutability, recycling rate and political stability scores.
The percentage of a commodity which is recycled. A higher recycling rate may reduce risk to supply. The availability of suitable substitutes for a given commodity.
The percentage of an element produced in the top producing country. The higher the value, the larger risk there is to supply. The percentage of the world reserves located in the country with the largest reserves. A percentile rank for the political stability of the top producing country, derived from World Bank governance indicators. A percentile rank for the political stability of the country with the largest reserves, derived from World Bank governance indicators.
Specific heat capacity is the amount of energy needed to change the temperature of a kilogram of a substance by 1 K. A measure of the stiffness of a substance. It provides a measure of how difficult it is to extend a material, with a value given by the ratio of tensile strength to tensile strain. A measure of how difficult it is to deform a material. It is given by the ratio of the shear stress to the shear strain.
A measure of how difficult it is to compress a substance. It is given by the ratio of the pressure on a body to the fractional decrease in volume. A measure of the propensity of a substance to evaporate. It is defined as the equilibrium pressure exerted by the gas produced above a substance in a closed system.
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Learning Objective Identify the properties of the noble gases. Key Points Noble gases are colorless, odorless, tasteless, and nonflammable gases under standard conditions.
In the periodic table, the noble gases are arranged according to their boiling point. Noble gases are widely used in different fields, from incandescent lighting to excimer lasers. Xenon is used as an anesthetic because of its high solubility in lipids, which makes it more potent than the usual nitrous oxide, and because it is readily eliminated from the body, which allows for faster recovery.
Xenon finds application in medical imaging of the lungs through hyperpolarized MRI. Radon, which is highly radioactive and is only available in minute amounts, is used in radiotherapy. Show Sources Boundless vets and curates high-quality, openly licensed content from around the Internet. Licenses and Attributions. However, it also has beneficial applications in radiotherapy, arthritis treatment, and bathing.
In radiotherapy, radon has been used in implantable seeds, made of glass or gold, primarily used to treat cancers. It has been said that exposure to radon mitigates auto-immune diseases such as arthritis. Some arthritis sufferers have sought limited exposure to radioactive mine water and radon to relieve their pain. The History The first person to discover the noble gases was Henry Cavendish in the late th century.
Argon In , John William Strutt discovered that chemically-obtained pure nitrogen was less dense than the nitrogen isolated from air samples. Helium Helium was first discovered in , manifesting itself in the solar spectrum as a bright yellow line with a wavelength of Radon In , while studying the decay chain of radium, Friedrich Earns Dorn discovered the last gas in Group radon.
The noble gases have the largest ionization energies, reflecting their chemical inertness. Because the atoms INCREASE in atomic size down the group, the electron clouds of these non polar atoms become increasingly polarized, which leads to weak van Der Waals forces among the atoms.
Thus, the formation of liquids and solids is more easily attainable for these heavier elements because of their melting and boiling points. Under standard conditions all members of the noble gas group behave similarly. All are monotomic gases under standard conditions. The size of the atom is positively correlated to several properties of noble gases. Overall, noble gases have weak interatomic forces, and therefore very low boiling and melting points compared with elements of other groups.
Applications of Noble Gases Helium Helium is used as a component of breathing gases due to its low solubility in fluids or lipids. Neon Neon has many common and familiar applications: neon lights, fog lights, TV cine-scopes, lasers, voltage detectors, luminous warnings, and advertising signs. One of the many colors of neon lights.
Argon Argon has a large number of applications in electronics, lighting, glass, and metal fabrications. Argon plasma light bulb.
Krypton Similarly to argon, krypton can be found in energy efficient windows. Krypton laser. Xenon Xenon has various applications in incandescent lighting, x-ray development, plasma display panels PDPs , and more.
Radon Radon is reported as the second most frequent cause of lung cancer, after cigarette smoking.
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