A 0.45g sample of mineral ore is analyzed for chromium and found to contain 0.560mg Cr2O4. Express the concentration of Cr2O3 in sample as a. Percent
b. Parts per thousand
c. Parts per million
d. Parts per billion

answer by yourhope:

how do models compare to real-world objects?

d. most models represent a real-world object in a simpler way.

: )

it is b that is the answer.

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.