General Science Daily Test Series 2

Methane is the main combustible component of biogas, with carbon dioxide being another major component.

Silver bromide is a photosensitive silver halide historically used in photographic films and papers.

Vulcanisation heats rubber with sulphur or suitable additives, creating cross-links that improve strength and elasticity.

PVC is formed by polymerisation of vinyl chloride, CH₂=CHCl.

Carnotite is a uranium- and vanadium-bearing mineral and is an important uranium ore.

HOOC–COOH is oxalic acid, whose molecular formula is C₂H₂O₄.

Platinum is a naturally white precious metal and is commonly described as white gold in general-knowledge contexts.

Calcium sulphate hemihydrate, CaSO₄·½H₂O, is commonly called Plaster of Paris.

Anthracite is the highest-rank common coal and has the greatest carbon content among the listed types.

Electrons in the highest occupied principal shell are called valence electrons and are present in the outermost orbit or shell.