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

• Carbon dioxide (CO₂) is used in fire extinguishers.
• It extinguishes fire by displacing oxygen and cooling the burning material.
• CO₂ fire extinguishers are especially effective for electrical and flammable liquid fires.
• Carbon dioxide is a colorless and non-flammable gas.
• It leaves no residue after use.

Last verified on 09-07-2026

Explanation

• Freezing Point: 0°C
• Fahrenheit: 32°F
• Kelvin: 273.15 K

Additional information:

• Boiling Point: 100°C (212°F or 373.15 K)
• Standard Atmospheric Pressure: 1 atm (760 mmHg)

Last verified on 06-07-2026

Explanation

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

Last verified on 13-03-2026

Explanation

• Fluorescent lamps mainly use argon gas (often with a small amount of mercury vapor).
• Electric current excites the gas and produces ultraviolet (UV) light.
• The UV light then hits the phosphor coating inside the tube.
• This coating produces visible light.
• Argon helps in starting and maintaining the discharge.

Last verified on 14-06-2026