All Free Everyday Science MCQs with Answers

501. What is the chemical formula of Ozone?

• A. H2O
• B. C12
• C. O3
• D. CH4

Explanation: Ozone is an allotrope of oxygen made of three oxygen atoms, so its formula is O₃. Ordinary oxygen gas contains two oxygen atoms per molecule and is written O₂.

502. 'Christian Friedrich Schönbein' discovery is___________?

• A. Ozone
• B. Radium
• C. Cholorine
• D. Neutron

Explanation: Christian Friedrich Schönbein identified ozone in 1839 while investigating the smell produced by electrical discharges. Ozone is the three-atom form of oxygen, O₃.

503. The metal, which is a constituent of vitamin B12 is____________?

• A. Iron
• B. Magnesium
• C. Zinc
• D. Cobalt

Explanation: Vitamin B12 contains cobalt at the centre of its corrin ring, which is why it is also called cobalamin. Iron is found in haemoglobin, not in the structure of vitamin B12.

504. Which Gas is included in Fry Chips Packets for safety?

• A. Nitrogen gas
• B. Carbon dioxide
• C. Oxygen
• D. Hydrogen

Explanation: Nitrogen is used because it is largely inert and displaces oxygen inside the packet, slowing oxidation and spoilage of the chips. Carbon dioxide can also be used in some food packaging, but nitrogen is the standard gas for fried-chip packets.

505. Enology is the study of____________?

• A. Wine
• B. Digestion
• C. Kidneys
• D. None

Explanation: Enology, or oenology, is the scientific study and production of wine. The other options refer to unrelated biological subjects.

506. Which metal is added to steel to make it stainless steel?

• A. Chromium
• B. Aluminium
• C. Carbon
• D. Copper

Explanation: Chromium forms a thin, self-repairing oxide layer on steel, protecting it from rust and corrosion. Aluminium can also resist corrosion, but it is not the defining addition in stainless steel.

507. What is the common name for the drug acetyl salicylic acid?

• A. Paracetamol
• B. Analgin
• C. Aspirin
• D. Penicillin

Explanation: Acetylsalicylic acid is the chemical name of aspirin, a drug used chiefly for pain, fever and inflammation. Paracetamol and analgin are different analgesic medicines, while penicillin is an antibiotic.

508. Which natural element has the highest melting point?

• A. Iron
• B. Tungsten
• C. Copper
• D. Silver

Explanation: Tungsten has the highest melting point among the listed elements, about 3,422°C, which is why it has been used in high-temperature applications. Iron, copper and silver melt at much lower temperatures.

509. At what temperature does silver melt?

• A. 275 °C
• B. 327 °C
• C. 961.8 °C
• D. 100 °C

Explanation: Silver melts at about 961.8 °C, because its metallic lattice requires a high temperature to break down. The lower values listed correspond roughly to other substances, not silver.

510. The reaction between methane and chlorine in diffused sunlight is__________?

• A. Oxidation
• B. Reduction
• C. Polymerisation
• D. Radical substitution

Explanation: In diffused sunlight, chlorine forms radicals that replace hydrogen atoms in methane, producing chloromethane and hydrogen chloride. This is therefore a free-radical substitution reaction rather than oxidation, reduction or polymerisation.