Noble Gas vs Inert Gas
Noble gases are inert gases, but all inert gases are not noble gases.
Noble gases are the group of elements which belongs to the group 18 of the periodic table. They are nonreactive or have a very low chemical reactivity. All the chemical elements in this group are monoatomic gases, colorless, and odorless. There are six noble gases. They are helium (He), neon (Ne), Argon (Ar), Krypton (Kr), Xenon (Xe), and Radon (Rn). Noble gases are different from other elements due to their minimal reactivity.
The reason for this can be explained by their atomic structure. All the noble gases have a completely-filled outer shell. In other words, they have competed octet which restricts them from participating in chemical reactions. Sometimes noble gases are also known as group 0 gases, considering their valency is zero. Though this is believed in common, later scientists have found some of the compounds made by these noble gases. So the reactivity follows the order Ne < He < Ar < Kr < Xe < Rn.
Noble gases have very weak inter-atomic interactions. Weak Van der Waals interactions are the inter-atomic forces which can be seen between noble gas atoms. These forces increase as the size of the atom increases. Because of the weak forces, their melting points and boiling points are very low. The boiling point and the melting point of an element have somewhat similar values.
Among all the noble gases, helium is little bit different. It has the lowest boiling point and the melting point from all. It is the smallest element. It shows superfluidity. So it cannot be solidified by cooling under standard conditions. From helium to radon down the group, atomic radius increases due to the increasing number of electrons and ionization energy decreases because expelling the outer most electrons becomes easier when the distance to it from the nucleus gets increased.
Noble gases are obtained from air by methods of liquefaction of gases and then fractional distillation. Among these elements, radon is radioactive. Its isotopes are unstable. 222Rn isotope has a half life of 3.8 days. When it decays it forms helium and polonium.
Noble gases are used as cryogenic refrigerants, for superconducting magnets, etc. Helium is used as a component of breathing gases, as a lifting gas in balloons and a carrier medium in gas chromatography. Normally noble gases are used to provide inert atmospheric conditions for experiments.
Inert gas is a gas which doesn’t undergo chemical reactions. This is considered in a set of given conditions, and when the conditions are changed, they may react again. Normally noble gases are inert gases. Nitrogen is also considered to be an inert gas under some conditions. These are used to prevent undesirable chemical reactions from happening.
What is the difference between Noble Gas and Inert Gas?
- Noble gases are inert gases, but all inert gases are not noble gases.
- Inert gases are not reactive under some conditions whereas noble gases can be reactive and make compounds.
- Noble gases are elemental, but inert gases may not. Inert gases may be compounds.