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CHEMISTRY BASICS

The Science of Molecular Formulas: What They Tell Us

Understand how to read molecular formulas and what information they contain about chemical compounds.

Decoding Molecular Formulas

Basic Format

A molecular formula shows which elements are present (using chemical symbols) and how many atoms of each element (using subscript numbers).

Example: H₂O (Water) - H = Hydrogen, 2 = Two hydrogen atoms, O = Oxygen (no number means 1)

Reading Complex Formulas

  • C₆H₁₂O₆ (Glucose) – 6 Carbon atoms, 12 Hydrogen atoms, 6 Oxygen atoms
  • NaCl (Table Salt) – 1 Sodium atom, 1 Chlorine atom
  • Fe₂O₃ (Rust) – 2 Iron atoms, 3 Oxygen atoms

What Formulas Don't Tell You

  • How atoms are arranged (structure)
  • Types of bonds between atoms
  • 3D shape of the molecule

Two compounds can have the same formula but different structures (isomers).

Why Element-Based Search Matters

CompoundLookup solves this by letting you select elements (C, H, O) and see ALL matching compounds—including every carbon-hydrogen-oxygen compound without memorizing formulas.

Try Element-Based Search