Science

• Periodic table

  Consists of several horizontal rows called the period or series
• Periods


  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
• Blocks

  • s-block
  • p-block
  • d-block
  • f-block
• About three-fourths of the discovered elements are metals