How To Read The Periodic Table

• Periods

  • The table is ‘periodic’ because elements with similar properties occur at regular intervals, i.e. periodically.
  • Therefore, the rows of the periodic table are called periods.

  
• Groups

  • Elements in the same column have the same number of electrons in their outer shell (the highest energy level).
  • Columns are called groups, and the group number equals the number of electrons an atom of that element has in its outer shell.

  
• Predicting chemical properties

  • Because all elements in a column have the same number of electrons in their outer shell, they have similar chemical properties.
  • This means they will all react in similar ways.