Explanation

• The cell wall of fungi is primarily made of chitin.
• It is a strong structural polysaccharide that provides support, strength, and protection.

Additional information:

• Cell membrane: Located inside the cell wall and controls the movement of substances into and out of the cell.
• Plants: Their cell walls are mainly made of cellulose.
• Bacteria: Their cell walls typically contain peptidoglycan.

Last verified on 15-10-2026

Explanation

• Sublimation is the process in which a solid directly changes into a gas without passing through a liquid phase.
• This endothermic phase transition
• Occurs when a substance absorbs enough energy to overcome intermolecular forces.
• Deposition: Gas to Solid (the reverse process).
• Examples: Dry ice, iodine, frost/snow.

Explanation

• An ionic bond forms when one or more electrons are transferred from one atom to another.
• Ionic bond: Formed by electron transfer, e.g., sodium chloride (NaCl).

Additional information:

• Covalent bond: Formed when atoms share electron pairs, e.g., water (H₂O).
• Metallic bonding: Positive metal ions are held together by attraction to delocalized electrons.
• Coordinate (dative) bond: A covalent bond in which both shared electrons are donated by one atom.

Last verified on 15-10-2026

Explanation

• An atom is the smallest possible particle of an element that can combine to form new compounds.
• Atoms are the building blocks of matter, and they cannot be broken down into smaller particles.

Last verified on 15-03-2026

Explanation

• An alkene is an unsaturated hydrocarbon that contains at least one carbon–carbon double bond (C=C). 
• C₂H₄ — Ethene: An alkene with one carbon–carbon double bond.

Additional information:

• C₂H₆ — Ethane: An alkane containing only single bonds.
• C₂H₂ — Ethyne: An alkyne containing a carbon–carbon triple bond.

Last verified on 15-10-2026

Explanation

• Nitrogen (N₂) → 78%

Additional information:

• Oxygen (O₂) → 21%
• Argon (Ar) → 0.93%
• Carbon dioxide (CO₂) → 0.04% (approximately)
• Other gases → Trace amounts

Last verified on 28-06-2026

Explanation

• Gamma rays have the highest frequency, shortest wavelength, and highest photon energy.
• They have strong penetrating ability and can pass through many materials.

Additional information:

Electromagnetic Spectrum (High to Low Frequency):

1. Gamma rays
2. X-rays
3. Ultraviolet rays
4. Visible light
5. Infrared rays
6. Microwaves
7. Radio waves

Last verified on 15-10-2026

Explanation

• A Barometer is an instrument used to measure air (atmospheric) pressure.
• It helps in weather forecasting by measuring changes in atmospheric pressure.
• The mercury barometer is the oldest type of barometer.
• It was invented by Evangelista Torricelli in 1643.
• Barometers are widely used in meteorology and aviation.

Last verified on 09-07-2026

Explanation

• The amplitude of a sound wave determines its loudness.
• Greater amplitude generally produces a louder sound.
• While smaller amplitude produces a quieter sound.

Additional information:

• Frequency: Determines pitch (high or low sound).
• Wavelength: The distance between two consecutive points in the same phase, such as two crests.

Last verified on 15-10-2026

Explanation

• A velocity–time graph shows how velocity changes with time.
• The slope gives acceleration.
• The area under the graph represents motion covered.
• It connects velocity with displacement.

Last verified on 22-05-2026