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- Name : Oxygen
- Symbol : O
- Atomic # : 8
- Atom weight: 15.9994
- Melting P. : -218.4
- Boiling P. : -182.962
- Oxidation : -2
- Pronounced : OK-si-jen
- From : Greek oxys + genes, "acid former"
- Identified : Carl Wilhelm Scheele in 1772
- Appearance : Colorless, odorless, tasteless gas; pale blue liquid
- Note : Vital for sustaining life
-
- [Properties]
-
- Oxygen is usually described as a colorless, odorless, tasteless gas
- that is essential to living organisms. Given the proper conditions
- for the reactions, oxygen reacts with virtually every known element
- to produce oxides.
- Oxygen heads the Group-VIA elements on the periodic table. The
- other members of this oxygen group are sulfur (S), selenium (Se),
- tellurium (Te), and polonium (Po). All except polonium are relatively
- plentiful in nature.
- There are two allotropes of oxygen, one composed of two oxygen
- molecules and the other composed of three. The latter is known as
- ozone. Ozone is a very strong oxidizing agent that is capable of adding
- an oxygen molecule to stable ions, thus changing sulfides to sulfates,
- dioxides to trioxides, and so on. This property makes it useful as a
- disinfectant and bleaching agent. It is also used in the treatment of
- sewage and the manufacture of chemicals.
- Ozone occurs naturally in the earth's upper atmosphere where it serves
- as an effective shield against harmful radiation from the sun.
- Commercial amounts are prepared by passing oxygen through an electric
- spark. The pungent odor often detected around electrical equipment is
- often that of ozone.
-