Explanation

• The atomic number of hydrogen is 1.
• It is the first element on the periodic table. 
• Named by: Antoine Lavoisier (1783)
• Atomic mass: 1.00784 u
• Appearance: Colorless gas
• Symbol: H
• Protons: 1
• Electrons: 1

Last updated 26-07-2026 by NA

Explanation

• The primary component of natural gas is methane (CH4).
• Making up 70% to 90% or more of its composition.
• It is a colorless, odorless, and highly flammable hydrocarbon gas.
• Characteristics: It is a fossil fuel, often found in rock formations alongside oil or on its own. 

Last updated question 15 March2026

Explanation

• Mercury Symbol: Hg
• Atomic number: 80
• Melting point: -38.83 °C
• Atomic mass: 200.59 u

Last verified on 13-03-2026

Explanation

• Gas molecules move freely in all directions because the particles are far apart.
• Gas particles have weak intermolecular forces and high kinetic energy.

Additional information:

• Solids: Vibrate in fixed positions
• Liquids: Move/slide around each other

Last verified on 06-10-2026

Explanation

• Nitrous oxide, commonly known as laughing gas.
• It is a colorless, non-flammable gas used in medicine.
• Nitrous oxide (N₂O) causes temporary laughing and relaxation.

Additional information:

• Nitrous oxide was discovered by Joseph Priestley in 1772.

Last verified on 18-01-2026