Berry Chemistry Form 6 Definition List Part 1

by BerryBerryTeacher

in Berry Reference (Notes)

This is a list of your berry important definitions for STPM Form 6 Chemistry. Sometimes the easiest way to understand and remember essential definitions and technical terms is to constantly recite it with your friends and question each other. So spread the word to your friends about this post and recite the definitions together.

STPM Chemistry Form 6 Definition List:

  1. The Hund Rule – orbital with the same energy level (degenerate orbitals), electron will occupy different orbital singly/one electron first with the parallel spin, before pairing.(Reject: same spin, spin with same direction) STPM 2008, 2007
  2. Pauli Exclusive Principle – Each orbital can hold a maximum of two electrons with opposite spin. (Reject: different spin) STPM 2007
  3. Aufbau principle – Electrons occupy orbitals with the lowest energy level first. (Reject: occupy lower energy first) STPM 2006, 2007
  4. Vapour pressure – the pressure exerted by a vapour that is in equilibrium with its liquid at a fixed temperature in a closed system. It is due to the collision of the vapour particles on the walls of the container. STPM 2004


  1. Molarity (M) [concentration of a fluid solution] – defined as the moles of a solute per volume of solution.
  2. Density [concentration of a fluid solution] – defined as the mass of solution per volume of solution.
  3. Dilutionaddition of solvent to a solution resulting in an increase in the volume of the solution and a decrease in the concentration of the solute in solution.
  4. Precipitation reaction (also refer to as double-displacement reaction) – a reaction that involve two aqueous salts being added together to form ions and a solid salt precipitate.


  1. Arrhenius acid – acid yields H3O+ when added to water
  2. Arrhenius base – base yields OH- when added to water
  3. Bronsted-Lowry acid (proton donor) – a substance that donate a proton, H+ to a base.
  4. Bronsted-Lowry base (proton acceptor) – a substance that accept a proton, H+ from an acid.
  5. Conjugate acid – a species (molecule or ion) formed when a proton is added to a base.
  6. Conjugate base – a species (molecule or ion) formed when a proton is removed from an acid.
  7. Lewis acid – an electron-pair acceptor.
  8. Lewis base – an electron-pair donor.
  9. Electrolyte (also electrolytic conductor) – a chemical compound that will conduct electricity in the molten state or in aqueous solution.
  10. Strong acid – an acid that is almost completely dissociated in aqueous solution. (Stronger the acid, the weaker its conjugate base)
  11. Weak acid – an acid that is only partially dissociated in aqueous solution. (Weaker the acid, the stronger its conjugate base)

So there you go!!! 17 of the most common definitions for STPM Form 6 Chemistry.

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