Teflon's monomer is: MCQ with Answer and Explanation

Explanation:
Graphite is used in electrodes (due to electrical conductivity) and as a moderator in nuclear reactors (to slow down neutrons). It is chemically stable and can withstand high temperatures. Diamond is an insulator. Fullerene is a nanomaterial. Charcoal is used as adsorbent and fuel. Graphite blocks are used in RBMK reactors (like Chernobyl) and in advanced gas-cooled reactors.

Explanation:
A solution turning red litmus blue is basic, so pH > 7. Among options, pH 9 is basic. pH 2 and 5 are acidic (blue litmus turns red). pH 7 is neutral. Litmus is a natural indicator extracted from lichens. Red litmus in base remains blue, blue litmus in acid turns red. Practical: Phenolphthalein gives pink in basic solution (pH > 8.3).

Explanation:
Hydrogen is considered the cleanest fuel because its combustion produces only water (2H₂ + O₂ → 2H₂O) and no greenhouse gases or toxic pollutants. Coal, wood, and diesel produce CO₂, CO, SO₂, and particulate matter, contributing significantly to air pollution and global warming.