Soap molecules have two ends with different properties. They are:
A. Hydrophobic and hydrophilic
B. Both A and B
C. Lipophobic and hydrophobic
D. Hydrophilic and lipophilic
Answer: Option B
Solution (By JKSSB Mock Tests)
A soap molecule has a long hydrocarbon chain which is hydrophobic (water-repelling) or lipophilic (fat-loving), and an ionic head (usually -COO⁻Na⁺) which is hydrophilic (water-loving) or lipophobic (fat-repelling). Both A and B correctly describe these dual properties essential for cleaning action.
Explanation:
A decomposition reaction is one where a single compound breaks down into two or more simpler substances. Heating potassium chlorate (KClO₃) breaks it down into potassium chloride and oxygen gas. A is combination, C is displacement, and D is double displacement.
Explanation:
Galvanization coats iron with zinc. Zinc is more reactive, corrodes first (sacrificial protection). Tin coating protects only if intact. Chromium is used for plating, nickel for alloys, but galvanizing specifically uses zinc.
Explanation:
Gamma rays are electromagnetic waves with no mass and no charge, thus they interact least with matter and have the highest penetrating power. Alpha particles (He nuclei) are stopped by paper. Beta particles (electrons) can be stopped by aluminum. Gamma requires thick lead or concrete.
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