Double and triple bonds form because:

a. one of the atoms in the molecule has more than eight valence electrons

b. single covalent bonds do not give all of the atoms in the molecule eight valence electrons

c. the ions involved have charges larger than one.

d. there is at least one hydrogen atom involved in the bond.

e. the atoms involved have high electronegativities.

B, Single Covalent bonds do not give all of the atoms in the molecule eight valence electrons.

Explanation:

In most cases, this is the reason why atoms form multiple covalent bonds. A prominent example would be . Nitrogen has 5 valence electrons each, meaning it needs 3 more electrons to fill its outer shell. Nitrogen can fill its outer shell by simply forming 3 covalent bonds with another Nitrogen atom.

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.