Wednesday, May 6, 2009

Elements & Periodic table


Elements



  • A substance which cannot be broken down into simpler substances by any chemical method.

  • 106 elements in the periodic table

Periodic Table



  • Elements are arranged according to their proton number (atomic number).


  • Every element is represented by a chemical symbol that consists either one capitalized letter ( e.g. Carbon -- C) or two letters with the first letter captilized (e.g. Helium -- He)


  • Elements are classified into metals & non-metals.


  • Elements are arranged in Group and Peiod

Group




  • Group-- the vertical column of elements of the Periodic Table.


  • Elements in the same group have similair chemical properties.


  • There are eight groups numbered Group I, II, III, IV, V, VI, VII, 0.

Period




  • Period -- the horizomtal row of elements of the Periodic Table.


  • Across a period from left to right, elements change from metallic to non-metallic


  • Example of elements found in each period number : Period Number 1--Hydrogen to Helium, Period Number 2-- Lithium to Neon, Period Number 3--Sodium to Argon, Period Number 4--Potassium to Krypton, Period Number 5--Rubidium to Xenon and Period Number 6-- Caesium to Radum.

Source: My brain and Sci notes.

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