Plaster of Paris is obtained by heating gypsum at: MCQ with Answer and Explanation

Explanation:
Redox stands for reduction-oxidation. In any redox reaction, oxidation (loss of electrons) and reduction (gain of electrons) always occur simultaneously. The substance oxidized acts as a reducing agent, and the substance reduced acts as an oxidizing agent. One cannot happen without the other.

Explanation:
Camphor sublimes—it directly changes from solid to vapor on heating without passing through the liquid phase. Other sublimable solids include naphthalene, iodine, ammonium chloride, and dry ice (solid CO₂). Sodium chloride, sugar, and sand melt or decompose on strong heating. Sublimation is used to separate sublimable substances from non-sublimable impurities. The process requires careful heating.

Explanation:
The magnetic quantum number (m) can only take integer values ranging from -l to +l. For n=3, l can be 2 (a d-orbital). If l=2, the possible values for m are -2, -1, 0, +1, +2. The value m=-3 is outside this range, making this set of quantum numbers impossible.