GSCE chemistry group 1, group 7 and group 0

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an ionic bond, resulting in the formation of a salt. The reaction between an alkali metal and a halogen is usually highly exothermic, which means it releases a large amount of heat. As a result, these reactions are often accompanied by the evolution of a flame or the emission of light. The specific characteristics of the salt that is formed depend on the particular alkali metal and halogen that are reacting. For example, the reaction between sodium and chlorine produces sodium chloride, which is a common table salt. The reaction between potassium and bromine, on the other hand, produces potassium bromide. The Noble Gases The noble gases are a group of elements that includes helium, neon, argon, krypton, xenon, and radon. They are so called because they are relatively unreactive and do not readily participate in chemical reactions. The noble gases are all monatomic gases, which means they exist as single atoms rather than as molecules. They are also all relatively nonpolar, which means they have little or no tendency to form chemical bonds with other atoms. As a result, the noble gases are often used as inert atmospheres in a variety of applications, including welding, light bulbs, and laboratory equipment. The noble gases have a number of interesting and useful properties. Helium, for example, is the second most abundant element in the universe and has a number of important industrial applications, including its use as a coolant in nuclear reactors and as a lifting gas in airships and balloons. Neon is used in neon lights and advertising signs, and argon is used as an inert gas in a variety of industrial processes. Xenon is used in some types of flash lamps and in the production of light-emitting diodes, and krypton is used in some types of fluorescent lamps.The noble gases all have simple and symmetrical molecular structures, which is one of the reasons why they are relatively unreactive. Helium, for example, has a single electron in its outermost energy level, which is completely filled and therefore does not have room for any additional electrons. This makes helium extremely stable and unreactive. Neon, which is the next element in the noble gas group, has a full outer energy level as well, but it has two electrons in its outermost energy level rather than just one. As a result, neon is also stable and unreactive, but it is slightly less so than helium. The remaining noble gases all have incompletely filled outer energy levels, which means they have room for additional electrons. However, they are still relatively unreactive because they have a high electron affinity. In addition, the outer energy levels of the noble gases are all relatively far from the atomic nucleus, which makes it difficult for other atoms to interact with them and form chemical bonds.