The raw materials for cement are: MCQ with Answer and Explanation

Explanation:
Burning of a candle involves combustion of wax (hydrocarbons) with oxygen to produce CO₂ and H₂O, a chemical change. The melting of wax is a physical change. Cutting wood is physical (size change). Freezing water is physical (state change). A chemical change results in new substances with different properties. Often irreversible.

Explanation:
Real gases deviate from ideal behavior due to intermolecular forces and molecular volume. Ammonia (NH3) has strong intermolecular hydrogen bonding and a relatively large molecular size compared to small, non-polar gases like He, H2, and N2. Therefore, ammonia exhibits the greatest deviation from ideal gas behavior.

Explanation:
Bakelite is a thermosetting plastic (phenol-formaldehyde resin). Once set, it cannot be remolded by heating because its polymer chains are cross-linked. Polyethylene, PVC, and nylon are thermoplastics—they can be repeatedly softened by heat and hardened on cooling. Thermosetting plastics are used for electrical switches, handles, and adhesives. Vulcanized rubber is also thermoset.