What is the maximum number of valence electrons an element can have?

Eight

Explanation:

The maximum number of electrons that can occupy the outermost energy level or valence shell of a Representative Element is eight (the exception is helium, which also exhibits a filled valence shell, but only it requires only 2 electrons).

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.