Which of the following gases is a major contributor to the greenhouse effect? MCQ with Answer and Explanation

Explanation:
PVC (polyvinyl chloride) is an addition polymer of vinyl chloride monomer (CH₂=CHCl). It is used for pipes, cables, flooring, and medical equipment. Teflon from tetrafluoroethene, polythene from ethylene, nylon is a polyamide (condensation polymer). PVC can be rigid or flexible depending on plasticizers added. It is a thermoplastic. Disposal of PVC by burning produces toxic HCl gas.

Explanation:
In a galvanic (voltaic) cell, chemical energy converts to electrical energy. Oxidation occurs at the anode, which is the negative electrode (electrons leave from it). Reduction occurs at the cathode, which is positive. This is opposite to electrolytic cell where anode is positive. Daniell cell: Zn anode (-), Cu cathode (+).

Explanation:
Metals are malleable (can be beaten into sheets), ductile (drawn into wires), and good conductors. Brittleness is a characteristic of non-metals and some metalloids; metals can deform without breaking. For example, gold is highly malleable.