Explanation

• Rectified spirit contains about 95% ethyl alcohol.
• It is highly purified alcohol obtained by repeated distillation.
• The remaining percentage is usually water.
• It is used in pharmaceuticals, laboratories, and industrial processes.

Last verified on 23-06-2026

Explanation

• The mass of a proton is approximately 1836 times greater than the mass of an electron.
• A proton is a positively charged particle found in the nucleus of an atom.
• It has almost the same mass as a neutron (slightly less).
• Electrons are much lighter compared to protons.

Last verified on 22-06-2026

Explanation

• The density of gases increases when pressure is increased because gas molecules come closer together.
• Density is the mass per unit volume of a substance.
• When pressure increases, the volume of gas decreases (at constant temperature), causing density to increase.
• This relationship follows Boyle’s Law.

Last verified on 21-06-2026

Explanation

• Lead pencil is made up of graphite.
• Graphite is a form (allotrope) of carbon.
• It is soft and leaves marks on paper easily.
• It is used in pencils because of its slippery layered structure.
• Despite the name “lead pencil,” it contains no real lead.
• Graphite was named by Abraham Gottlob Werner in 1789.

Last verified on 21-06-2026

Explanation

• Diamond is a naturally occurring allotropic form of carbon.
• Allotropy means a single element can exist in more than one form with different structures and properties.
• It is extremely hard.
• It has a high melting point.
• It is widely used in jewelry and cutting tools.

Additional information:

• Graphite – soft, good conductor
• Fullerenes (C60) – spherical molecules
• Carbon nanotubes – tubular, high strength
• Amorphous carbon – coal, soot
• Lonsdaleite – hexagonal diamond

Last verified on 17-01-2026