2.2 Conservation of Mass in Chemical Equations

chemistry

Writing Word Equations

Word equations require careful examination to be written correctly.

  • The chemical symbol is used for most elements but not in a compound
    • Be careful of diatomic and polyatomic elements< such as O2, P4 and S8
    • The "special seven" are all diatomic elements
      • H2, N2, O2, F2, Cl2, Br2, I2
  • Several common covalent molecules containing hydrogen have common names that do not help in writing chemical formulas
    • For example, methane = CH4, glucose = C6H12O6, Ethane = C2H6, Ammonia = NH3

The pink shaded area in the picture below shows the diatomic atoms.
diatomics