Explanation

• Compressibility describes how much a gas's volume decreases when pressure is applied.
• At constant temperature, increasing pressure generally decreases the volume of a gas, according to Boyle's law.
• Real gases may deviate from ideal behaviour, especially at high pressures.

Last verified on 01-11-2026

Explanation

• The rate of diffusion depends on particle size and their kinetic energy.
• Smaller and lighter particles generally diffuse faster than larger and heavier particles.
• Higher temperature increases the average kinetic energy of particles, causing faster diffusion.

Last verified on 01-11-2026

Explanation

• Density is the mass per unit volume of a substance.
• Density is calculated by dividing the mass of a substance by its volume.
• The SI unit of density is kilogram per cubic metre (kg/m³).

Last verified on 25-10-2026

Explanation

• The rate of evaporation increases with an increase in the exposed surface area because more liquid molecules can escape into the air.
• Evaporation occurs at the surface of a liquid and can take place at temperatures below its boiling point.

Last verified on 01-11-2026

Explanation

• Allotropy is the ability of an element to exist in two or more different structural forms in the same physical state.
• Oxygen exists as dioxygen (O₂) and ozone (O₃).
• Sulphur exists in different allotropic forms, mainly rhombic and monoclinic sulphur.

Last verified on 01-11-2026

Explanation

• Metallic bonding consists of positive metal ions surrounded by a sea of delocalized, freely moving electrons.
• These mobile electrons allow metals to conduct electricity and heat efficiently.
• The attraction between positive metal ions and delocalized electrons holds the metallic structure together.

Last verified on 01-11-2026

Explanation

• Electron affinity measures the energy change when a neutral gaseous atom gains an electron to form a negative ion.
• Elements with a greater tendency to accept electrons generally have a higher electron affinity.

Additional information:

• Electronegativity describes an atom's ability to attract shared electrons in a chemical bond.

Last verified on 01-11-2026

Explanation

The M orbit, also known as the third electron shell.

• It can hold a maximum of 18 electrons.

Additional information:

The K orbit, also known as the first electron shell.

• It can hold a maximum of 2 electrons.

The L orbit, also known as the second electron shell.

• It can hold a maximum of 8 electrons.

Last verified on 01-11-2026

Explanation

• Fluorine is more reactive than chlorine and can displace chlorine from sodium chloride.
• The liberated chlorine gas has a characteristic greenish-yellow colour.

Last verified on 01-11-2026

Explanation

• Alkaline earth metals lose 2 electrons to form M2+ ions.
• Halogens gain electrons to form X- ions.
• Both oxidation and reduction occur, so it is a redox reaction.

Last verified on 01-11-2026