Explanation

• Black Gold: Petroleum (Crude Oil)
• Color: Dark black / brownish black
• Main Uses: Fuel, petrol, diesel, kerosene, plastics
• Importance: Backbone of modern industry and transport

Additional information:

• Top Oil-Producing Countries:
  1. Saudi Arabia
  2. USA
  3. Russia
  4. Iraq
  5. Iran

Last verified on 16-06-2026

Explanation

• The instrument used to measure temperature is called a thermometer.
• A thermometer shows how hot or cold an object or place is.

Additional information:

• Barometer measures air pressure.
• Hygrometer measures humidity (moisture in air).

Last verified on 16-06-2026

Explanation

• Necrophobia is the abnormal fear of death or dead bodies.
• It is a type of specific phobia related to mortality.
• Affected individuals feel extreme anxiety when thinking about death.
• It may also include fear of corpses or funerals.
• It is a psychological anxiety disorder.

Last verified on 10-06-2026

Explanation

• Ornithology is the branch of zoology that deals with the study of birds.
• It includes bird behavior, classification, and migration patterns.
• Scientists who study birds are called ornithologists.

Last verified on 10-06-2026

Explanation

• Herpetology is the branch of zoology that studies reptiles and amphibians.
• Reptiles include: snakes, lizards, crocodiles, turtles.
• Amphibians include: frogs, toads, salamanders.
• The word comes from Greek “herpeton” meaning creeping animal.

Last verified on 09-06-2026

Explanation

• A stretched spring possesses potential energy.
• When a spring is stretched or compressed, energy is stored in it.
• This stored energy is called elastic potential energy.
• It can be converted into kinetic energy when released.
• The more the stretch, the more energy is stored.

Last verified on 08-06-2026

Explanation

Surface area = 4πr², Volume = 4/3πr³.  

Surface area is just derivative of volume w.r.t r.

2πr is circumference of a circle, not volume at all.

Last verified on 07-06-2026

Explanation

• Smog is a form of air pollution formed by smoke + fog.
• It mainly occurs in big cities due to vehicle and factory emissions.
• It reduces visibility and causes breathing problems.
• Smog is a serious environmental and health hazard.

Last verified on 06-06-2026

Explanation

• Oxidation of secondary alcohols produces ketones.
• Secondary alcohols have –OH group attached to a carbon bonded with two other carbons.
• During oxidation, hydrogen is removed and a carbonyl (C=O) group is formed.

Additional information:

• Primary alcohol → Aldehyde → Acid
• Secondary alcohol → Ketone (stops here)
• Tertiary alcohol → No easy oxidation

Last verified on 05-06-2026

Explanation

• Natural rubber consists of polymers of isoprene (C₅H₈).
• Isoprene is a five-carbon unsaturated hydrocarbon.
• Natural rubber is chemically known as cis-1,4-polyisoprene.
• It is obtained from the latex of rubber plants.

Last verified on 05-06-2026