Oxygen (O2)  is an active, colorless, odorless and tasteless. It  has numerous uses in steel making and other metals refining & fabrication processes, petroleum processing, glass/ceramic & pulp/paper manufacture. It is used for environmental protection in municipal and industrial effluent treatment plants and facilities. Oxygen (O2)   is widely used with fuel gases in gas welding, gas cutting, oxygen scarfing, flame cleaning, flame hardening, and flame straightening. In gas cutting, the oxygen must be of high quality to ensure a high cutting speed and a clean cut

Argon (Ar)  is a monatomic, colorless, odorless, tasteless and nontoxic gas. It is valued for its total inertness in particular at high temperatures.  Argon is used in critical industrial processes such as the manufacturing of high quality stainless steels, plasma cutting and production of impurity-free silicon crystals for semi-conductor manufacture. Pure argon (Par) & argon (Ar)  mixed with various other gases, is used as a shield gas in TIG & MIG welding which employs a consumable wire feed electrode. The function of the shielding gas is to protect the electrode and the weld pool against the oxidizing effect of air. Pure argon is often used with aluminum. 

Nitrous Oxide (N2O) is  a colorless, non-flammable gas with a slightly sweet taste.  It is a very common inhalation anesthetic that offers analgesia, a nxiolysis , and sometimes amnesia,   k nown as "laughing gas" due to the euphoric or exhilarating effect of inhaling it. Nitrous Oxide (N2O)  is also used in the food industries, such as in whipped cream canisters &  a food additive as a propellant. In  automobile  industries, it is uses as an engine booster, an additive to fuels to increase available oxygen  in combustion.