The U. S. Public Health Service recommends the fluoridation of water as a means for preventing tooth decay. The recommended concentration is 1.0 mg F per liter. The presence of calcium ions in hard water can precipitate the added fluoride. What m molarity of calcium is at the USPHS recommended level? (Ksp for CaF2 is 4.0 × 10-11.)

water and alcohols have similar properties because water molecules contain hydroxyl groups that can form hydrogen bonds with other water molecules and with alcohol molecules, and likewise alcohol molecules can form hydrogen bonds with other alcohol molecules as well as with water.

the pseudoscience are like beliefs, theories, or like practices that are considered scientific

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.