The average atomic mass of oxygen is 15.9994 amu. the atomic masses of its three isotopes are as follows: o-16: 15.995 amu; o-17: 16.999 amu; o-18: 17.999 amu which isotope is most likely to have the greatest abundance in nature?

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.