Question

Formula H₂O is of the chemical compound –

• A. Air
• B. Water
• C. Earth
• D. None of these

Hint:

H₂O = Water (2 Hydrogen + 1 Oxygen) CO₂ = Carbon Dioxide NaCl = Salt CH₄ = Methane NH₃ = Ammonia Remember: The subscript tells the number of atoms of that element in one molecule.

Answer 1

The Correct Option is B

Chemical formulas represent the composition of compounds using element symbols and subscripts. H₂O is one of the most recognized chemical formulas. Understanding H₂O:

H = Symbol for Hydrogen
O = Symbol for Oxygen
₂ = Subscript indicating two atoms of hydrogen
H₂O = Two hydrogen atoms bonded to one oxygen atom
Properties of Water (H₂O):

Colorless, odorless, tasteless liquid at room temperature
Universal solvent
Boils at 100°C (212°F) at sea level
Freezes at 0°C (32°F)
Essential for all known forms of life
Why Water is Correct:

H₂O is the chemical name for water
Water molecule consists of one oxygen atom covalently bonded to two hydrogen atoms
The name "water" comes from Old English "wæter"
Why Other Options are Incorrect:

(A) Air:

Air is a mixture of gases, not a single compound
Composition: Nitrogen (78%), Oxygen (21%), Argon (0.9%), CO₂, etc.
No single chemical formula

(C) Earth:

Earth is a planet, not a chemical compound
Composed of many elements and compounds

(D) None of these:

Incorrect because H₂O is definitely water

Other Common Chemical Formulas: \begin{tabular}{|l|l|} \hline Compound & Formula
\hline Carbon Dioxide & CO₂
Methane & CH₄
Ammonia & NH₃
Sodium Chloride (Salt) & NaCl
Glucose & C₆H₁₂O₆
\hline \end{tabular} Final Answer: Water