Noble Gases

Noble Gases Group number: 0 Most gases are made up of molecules (e.g. H2, O2). However, the noble gases are so unreactive that they are found as the atoms themselves. They are called monatomic gases ('one atom' gases). The noble gases are very unreactive. This is because...Chemical reactions involve the electrons in the outer shells of atoms. Most atoms have a tendency to have their outer shell completely full of electrons. With full outer shells, atoms are stable (the noble gases are stable because their outer shells are full).Atoms can give, take or share electrons with other atoms to get full outer shells.  Physical PropertiesBoiling point: Low, decreases down groupDensity: Low, increases down groupReactivity: Unreactive, increases down group UsesHelium: Used to cool metals down (because if a metal is cooled down to a very low temperature             it loses its electrical resistance) e.g. helium boils at -269°C. It is used to…