oxidation number

• OXIDATION NUMBER - To track the electrons in compounds and reactions especially compounds part of a covalent bond (sharing of electrons) chemist devised a tool to help track electrons trough assigning “fictional charge” to an atom.
• it is assumed that oxidation number is the charged given to elements would have if the molecule was ionic.
• The term oxidation was first used by Antoine Lavoisier to signify the reaction of a substance with oxygen.
• RULES FOR GETTING OXIDATION NUMBER

  1. Elements by itself: 0 (e.g., Cl2, Na, S6, P4 )
  2. Elements in Group 1-A: +1
  3. Elements in Group 2-A: +2
  4. Halogens (Group 17A) is usually -1, but +1 with oxygen or except when a central atom or when combined with a more electronegative element
  5. Monoatomic ion is equal to its ion charge (e.g., K+ =+1, Mg 2+=2+)
  6. Hydrogen is usually +1, with non metals. -1 with metals.
  7. Oxygen: usually -2,
  8. Fluorine: always -1
  9. Sum Of oxidation number for neutral compound is zero
  10. Sum of oxidation number for polyatomic ion is equal to its ion charge