VALENCE ELECTRONS

• What does the group number indicate for main group elements in the periodic table?

  It corresponds to the number of valence electrons.
• How do you determine valence electrons for main group elements?

  • Group 1: 1 valence electron
  • Group 2: 2 valence electrons
  • Groups 13-18: Last digit of group number
• How many valence electrons do alkali metals have?

  1 valence electron
• How many valence electrons do alkaline earth metals have?

  2 valence electrons
• How many valence electrons do elements in Group 13 have?


  3 valence electrons
• How many valence electrons do elements in Group 14 have?


  4 valence electrons
• How many valence electrons do elements in Group 15 have?

  5 valence electrons
• How many valence electrons do elements in Group 16 have?

  6 valence electrons
• How many valence electrons do halogens (Group 17) have?

  7 valence electrons
• How many valence electrons do noble gases (Group 18) have?

  8 valence electrons (except Helium)
• How many valence electrons does Helium have?

  2 valence electrons
• What is unique about the valence electrons of transition metals?

  • Complex electron configurations
  • Involves outermost s and d orbitals
  • Varying valence states
• How many valence electrons does Carbon (Group 14) have?


  4 valence electrons
• How many valence electrons does Oxygen (Group 16) have?

  6 valence electrons
• How many valence electrons does Sodium (Group 1) have?

  1 valence electron
• How many valence electrons does Chlorine (Group 17) have?

  7 valence electrons
• How does group number relate to chemical reactivity in elements?

  • Similar valence electron configurations
  • Similar chemical properties
  • Predicts chemical reactivity