CIE IGCSE Chemistry

Revision Notes

9.1.1 The Periodic Table

Classifying Elements & Predicting Properties

Periodic table

  • Elements are arranged on the Periodic Table in order of increasing atomic number, where each element has one proton more than the element preceding it
  • The table is arranged in vertical columns called Groups numbered 1 – 8 and in rows called Periods
  • Period: these are the horizontal rows that show the number of shells of electrons an atom has
    • Eg elements in Period 2 have two electron shells, elements in Period 3 have three electron shells
  • Group: these are the vertical columns that show how many outer electrons each atom has
    • Eg Group 4 elements have atoms with 4 electrons in the outermost shell, Group 6 elements have atoms with 6 electrons in the outermost shell


The-Periodic-Table-of-the-Elements, IGCSE & GCSE Chemistry revision notesAll elements are arranged in the order of increasing atomic number from left to right


Predicting properties using the Periodic table

  • Because there are patterns in the way the elements are arranged on the Periodic table, there are also patterns and trends in the chemical behaviour of the elements
  • There are trends in properties down Groups and across a Period
  • All of the Group I elements, for example, react very quickly with water
  • In this way the Periodic table can be used to predict how a particular element will behave

Author: Morgan

Morgan’s passion for the Periodic Table begun on his 10th birthday when he received his first Chemistry set. After studying the subject at university he went on to become a fully fledged Chemistry teacher, and now works in an international school in Madrid! In his spare time he helps create our fantastic resources to help you ace your exams.

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