Antoine Lavoisier, an 18th-century French chemist, is widely considered the father of modern chemistry. He transformed chemistry from a qualitative to a quantitative science, established the law of conservation of mass, debunked the phlogiston theory, and helped reform chemical nomenclature.
Explanation:
Temporary hardness is due to dissolved bicarbonates of Ca and Mg, which can be removed by boiling: Ca(HCO₃)₂ → CaCO₃↓ + H₂O + CO₂. Permanent hardness is caused by chlorides and sulfates of Ca and Mg, not removed by boiling. Sodium bicarbonate does not cause hardness. Methods to remove permanent hardness include treatment with washing soda (Na₂CO₃), ion exchange, or calgon.
Explanation:
Stratospheric ozone absorbs harmful UV-B and UV-C radiation from the sun, protecting living organisms. Depletion by CFCs increases UV at surface. Infrared is absorbed by greenhouse gases.
Explanation:
The ozone layer is located in the lower stratosphere (~15-35 km altitude), where ozone concentration is highest. It absorbs harmful ultraviolet radiation (UV-B and UV-C) from the sun. Ground-level ozone (troposphere) is a pollutant and component of smog, harmful to health. Ozone depletion is caused by chlorofluorocarbons (CFCs) which release chlorine atoms that catalytically destroy O₃.
No comments yet. Be the first to start the discussion!