The Noble gases are a group of elements that possess many similar characteristics and properties. Noble gases as odorless, colorless, tasteless and non-flammable. They have a very low chemical reactivity. The six naturally occurring noble gases currently known are Argon (Ar), Neon (Ne), Helium (He), Krypton (Kr), Xenon (Xe) and radioactive Radon (Rn). Noble gases are used extensively in lighting welding and space exploration. Helium is also used in blimps and hot air balloons.
Why are Noble Gases Unreactive?
The atomic structure of Noble gases is the reason that they are unreactive or have little tendency to react with other substances. Each atom is made up of a nucleus and a number of electrons that orbit the nucleus. The number of electrons that an atom has in its outer shell or valence shell determines how reactive an atom is. If an atom has few electrons in its outer shell or has an outer shell that is almost to capacity then the atom will be very reactive. The atom will be trying to attract more electrons from other atoms, meaning that it will react easily with other substances. Noble gases consist of atoms that have a full outer shell or valence shell. This means that they do not attract or require electrons from other atoms and therefore have no reason to react with them. Noble gases are very stable chemical elements. In fact scientists have only been able to create a few hundred noble gas compounds. These are usually achieved with the heavier noble gases such as radon, xenon and krypton where the outer electrons are easier to remove due to weaker electromagnetic bonds.
The following video further explains the properties of noble gases: