Essay On Thallium Neon And Iodine

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The emission spectrum of an element is the spectrum of frequencies in electromagnetic radiation emitted due to a specific atom's electrons, creating a transition from a high energy to a low energy state. There are many possible electron transitions for each different atom in which the transition has a specific energy difference. The collection of different transitions leads to different radiated wavelengths and in turn makes up an emission spectrum. Each element's emission spectrum is unique and completely different form other elements on the periodic table. In order to reiterate this statement elements; thallium, neon and iodine will be compared and explained. Thallium Thallium was discovered by Sir William Crookes in 1861, in London. In 1850 Crookes had been given a deposit containing selenium from a sulfuric acid factory in Tilkerode. Crookes extracted the selenium and was left with residues which appeared to contain tellurium. Crookes named thallium after the Greek word ‘thallos’ which means a green shoot or twig, in reference to the unique green spectral line which identifies the element in its emission spectra. Thallium possesses properties such as; soft, malleable, and low-melting. It is a silvery metal that releases a bluish oxide once it is heated into the air. Its appearance is often misconstrued for lead. Thallium can easily be cut using every day utensils (such as a knife) because of its malleability. Once thallium is presented in water, poisonous thallium hydroxide or TIOH is created. The metal slowly dissolves in hydrochloric acid, becomes diluted in sulfuric acid and rapidly dissolves in nitric acid. The colorless and odorless thallium sulfate is used in rat poisoning and as an insecticide. This use of tha... ... middle of paper ... ...sed using a spectroscope. Neon is often used in signs because of its production of an unmistakable bright reddish-orange light. Although still referred to as "neon", other colors are generated with the variety of noble gases and by various colors of fluorescent lighting. Neon is also used in vacuum tubes, high-voltage indicators, lightning arrestors, wave meter tubes, television tubes, and helium neon lasers. When Neon is liquefied it is commercially used as a cryogenic refrigerant and the lower temperature range becomes more attainable with more the extreme liquid helium refrigeration. Neon both as a gas and a liquid are relatively expensive for example; the price of liquid neon even in small quantities can be more than 55 times that of liquid helium. The reason for neon's expense is because of neon’s rarity which unlike helium, can only be obtained from the air.

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