Explanation

• Calcium (Ca) is an alkaline earth metal belonging to Group 2 of the periodic table.
• Its atomic number is 20.
• Mercury (Hg) is a liquid metal at room temperature.
• Its atomic number is 80.
• Mercury has a boiling point of approximately 356.7°C.

Last verified on 09-11-2026

Explanation

• 24-karat (24K) gold is considered the "best"
• Purity: 99.9% pure gold.
• Color: Rich, deep, bright yellow.

Additional information

• 22K Gold: 91.7% pure gold. It is mixed with harder metals like silver or copper.
• 18K Gold: 75% pure gold. It is highly durable and excellent for diamond settings 
• Carat is the unit of measurement for the physical weight of diamonds/gold.

Last updated by NA on 16-07-2026

Explanation

• Copper (تانبا) is a good conductor of electricity.
• It allows electric current to flow easily.

Additional information:

• Metals are generally good conductors.
• Non-metals usually do not conduct electricity.
• Good Conductors: Copper, Silver, Gold, Aluminum, Graphite
• Bad Conductors: Plastic, Rubber, Wood, Glass, Air

Last verified on 07-06-2026

Explanation

• Metals allow electricity to pass through them easily.
• Among all metals, silver has the highest electrical conductivity.
• Copper and gold are also very good conductors.
• Silver is widely used in high-precision electrical applications.
• Copper is commonly used in wiring due to cost-effectiveness.

Last verified on 16-05-2026

Explanation

• Protons and neutrons form the nucleus of an atom.
• Together, they are called nucleons because they are nuclear particles.

Additional information:

• Nucleons determine the mass of an atom.
• Isotopes are atoms of the same element with different number of neutrons.

Last verified on 07-03-2026