Acid rain corrodes marble (CaCO₃) because: MCQ with Answer and Explanation

Explanation:
Roasting is the process of heating the concentrated ore (usually sulfide ores) strongly in the presence of excess air below its melting point. It converts the ore to its oxide form and removes volatile impurities as gases (e.g., 2ZnS + 3O₂ → 2ZnO + 2SO₂).

Explanation:
Thomson used cathode ray tubes to discover the electron and measure its charge-to-mass ratio (e/m). He proposed the 'plum pudding' model. Proton identified by Rutherford, neutron by Chadwick.

Explanation:
DAP, (NH₄)₂HPO₄, supplies nitrogen (18% N) and phosphorus (46% P₂O₅). It is a widely used phosphorus-rich fertilizer. Potassium is not present. NPK complex fertilizers provide all three. DAP is highly water-soluble, making phosphorus readily available. In soil, DAP temporarily increases pH around granules due to ammonia, but later nitrification lowers pH. Application: usually at sowing time.