Hamad stated that nitrogen gas is noncombustible so is water vapour. if both nitrogen and water are in gaseous state then why the term gas and vapour were used by hamad?

Unlike clouds, fog, or mist which are simply suspended particles of liquid water in the air, water vapour itself cannot be seen because it is in gaseous form. Water vapour in the atmosphere is often below its boiling point. When water is boiled the water evaporates much faster and makes steam.

Explanation:

Unlike clouds, fog, or mist which are simply suspended particles of liquid water in the air, water vapour itself cannot be seen because it is in gaseous form. Water vapour in the atmosphere is often below its boiling point. When water is boiled the water evaporates much faster and makes steam.

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on passing the small ampere of electric current through the tube made of ar and hg of cfl generates uv rays which excites the fluorescent and thus emits the high radiation by consumption of just 5- 12 w in comparison to incandescent light which requires more power such as around 40 - 55 w to lighten.

moreover the life span of fluorescent or cfl is around 8000 h whereas the life span of incandescent is around 1200 h

hence, the building installed with incandescent lights bears more electricity bill.