Chemistry - Metals & Non-metals Questions for SSC CGL (with Answers)

Answer: D. Potassium

Potassium is the most reactive among these; gold is the least.

Answer: B. Diamond

Diamond is the hardest natural substance known.

Answer: D. Copper and zinc

Brass is made of copper and zinc.

Answer: B. Sodium

Sodium is so reactive that it is kept in kerosene to avoid contact with air and moisture.

Answer: C. Bauxite

Bauxite is the main ore from which aluminium is extracted.

Answer: B. Gallium

Gallium has a low melting point (about 30 °C) and melts on the palm.

Answer: D. Copper

Copper is less reactive than hydrogen, so it cannot displace hydrogen from dilute acids.

Answer: D. Joining broken railway tracks

The highly exothermic thermit reaction produces molten iron, used to weld railway tracks.

Answer: C. Silver

Silver has the highest electrical conductivity among metals.

Answer: A. Graphite

Graphite, an allotrope of carbon, conducts electricity because of free electrons.

Answer: A. Amphoteric oxides

Oxides that react with both acids and bases to form salt and water are amphoteric.

Answer: B. Concentrated HCl and concentrated HNO3 in the ratio 3 : 1

Aqua regia is 3 parts concentrated hydrochloric acid to 1 part concentrated nitric acid.

Answer: B. 22 parts gold alloyed with 2 parts copper or silver

22-carat gold has 22 parts of gold and 2 parts of copper or silver out of 24.

Answer: D. Roasting

Roasting converts sulphide ores to oxides by heating in excess air; calcination is for carbonates.

Answer: B. Anode

The impure metal is the anode; pure copper deposits on the cathode.