exhibiting maximum covalency in compound

exhibiting amphoteric nature in their oxides

forming covalent halides

forming polymeric hydrides

Electron affinity

Bond dissociation energy

Hydration enthalpy

Ionization enthalpy

It is used to fill gas balloons instead of hydrogen because it is lighter and non–inflammable

It is used in gas – cooled nuclear reactors

It is used to produce and sustain powerful superconducting reagents

It is used as cryogenic agent for carrying out experiments at low temperatures

oxygen in air reacts with the emitted HCI gas to form a cloud of chlorine gas

strong affinity of HCI gas for moisture in air results in forming of droplets of liquid solution which appears like a cloudy smoke

due to strong affinity for water, concentrated hydrochloric acid pulls moisture of air towards it self. This moisture forms droplets of water and hence the cloud.

concentrated hydrochloric acid emits strongly smelling HCI gas all the time.