Which of the following statements is correct regarding the Tyndall effect? MCQ with Answer and Explanation

Explanation:
Magnesium (Z=12): configuration 2,8,2. Period = number of shells = 3; Group = 2 (2 valence electrons). Be is Group 2, Period 2; Ca is Group 2, Period 4; Sr Period 5.

Explanation:
Autocatalysis occurs when one of the products of a chemical reaction acts as a catalyst for that same reaction. As the reaction proceeds and the product accumulates, the rate of the reaction increases. A classic example is the oxidation of oxalic acid by potassium permanganate, where the Mn2+ ions produced catalyze the reaction.

Explanation:
CFCs were widely used as refrigerants (Freon), propellants in aerosol sprays, foam blowing agents, and solvents. They are chemically stable in the troposphere, drift to the stratosphere where UV breaks them, releasing Cl atoms that destroy ozone. Automobiles emit CO₂, NOx. Volcanoes emit SO₂. Fertilizers lead to N₂O.