Trends in the periodic table

• What is observed in the periodic table regarding physical properties?

  A number of repeating patterns
• How does the atomic radius change across a period?

  The atomic radius decreases
• What does electronegativity measure?

  The tendency of an atom to attract electrons
• Why does electronegativity increase across a period?

  Due to greater nuclear charge attracting electrons
• What happens to the ionic radius of positive ions?

  The ionic radius decreases
• How do negative ions compare to the atoms they formed from?

  Negative ions are larger than their parent atoms
• What is the trend in melting points across groups 1 to 4?

  Melting points tend to increase
• What happens to boiling points across groups 5 to 0?

  Boiling points tend to decrease
• How does electronegativity change as you go up a group?

  Electronegativity increases
• What is the reason for increased metallic character down a group?

  Atoms increase in radius and have more shielding
• Why can outer electrons be lost more readily in lower groups?

  Electrons can move more freely
• What explains the trends in melting and boiling points of metals?

  • Melting and boiling points increase with metallic bond strength
  • Positive metal ions get smaller across the period
  • Charge of ions increases with more delocalised electrons
• What type of structures do carbon and silicon have?

  Giant covalent or macromolecular structures
• What type of bonding changes across the period?

  From metallic to covalent bonding
• What type of forces exist between elements from groups 5, 6, 7, and O?

  Weak London forces
• How does the strength of metallic bonds affect melting and boiling points?

  Stronger metallic bonds lead to higher melting points
• What happens to the electrostatic attraction between the nucleus and outer electrons down a group?

  The attraction becomes weaker
• What is the trend in melting points across groups 5 to 0?

  Melting points tend to decrease