Periodicity

• Which elements are included in Period 3?

  Sodium to Argon
• What is important to know about electron configurations for Period 3 elements?

  They involve adding one electron each time
• What is the electron configuration for Sodium?

  1s² 2s² 2p⁶ 3s¹
• What is the electron configuration for Argon?

  1s² 2s² 2p⁶ 3s² 3p⁶
• What blocks are present in the periodic table?

  S, P, D, and F blocks
• What does the S block contain?

  Elements filling the S orbital
• How does atomic radius change across Period 3?

  It decreases across the period
• Why does atomic radius decrease across Period 3?

  More protons create stronger attraction
• What happens to atomic size when moving down a group?

  Atomic size increases down the group
• What is ionization energy?

  Energy required to remove an electron
• How does ionization energy change across Period 3?

  It generally increases across the period
• What causes the dip in ionization energy between Magnesium and Aluminium?

  Aluminium has an additional electron in a higher energy level
• Why does ionization energy decrease from Phosphorus to Sulfur?

  Repulsion from paired electrons in Sulfur
• What is the trend in melting and boiling points across Period 3?

  There is no general trend
• What are the key trends across Period 3 elements?

  • Atomic radius decreases
  • Ionization energy generally increases
  • Melting and boiling points vary without a clear trend
• What factors affect atomic radius in Period 3?

  • Same energy level across the period
  • Increased protons lead to stronger attraction
  • No additional shielding from new shells
• What factors influence ionization energy in Period 3?

  • Increased protons lead to stronger attraction
  • Electron configuration affects ease of removal
  • Repulsion from paired electrons can lower energy
• What is the significance of electron configurations in Period 3?

  • Determines atomic radius
  • Influences ionization energy
  • Affects chemical properties and bonding
• What is the focus of the discussion in the material?

  Ionization energies and melting/boiling points
• What is the reason for changes in melting and boiling points across the period?

  Due to bonding types and structures
• Which elements are listed across the top?

  • Sodium
  • Magnesium
  • Aluminium
  • Silicon
  • Phosphorus
  • Sulfur
  • Chlorine
  • Argon
• What type of bonding is present in sodium, magnesium, and aluminium?

  Metallic bonding
• What type of bonding is present in silicon?

  Macromolecular covalent bonding
• What type of bonding is present in phosphorus, sulfur, and chlorine?

  Simple molecular covalent bonding
• What is the nature of argon in terms of bonding?

  Monatomic with weak van der Waals forces
• Why does the melting and boiling point increase from sodium to aluminium?

  Due to increased charge and delocalized electrons
• How does the size of ions affect metallic bonding strength?

  Smaller ions lead to stronger attraction
• What happens to the melting point when moving to silicon?

  It jumps up due to strong covalent bonds
• What is required to melt silicon?

  Breaking many strong covalent bonds
• Why do phosphorus, sulfur, and chlorine have lower melting and boiling points?

  Due to simple molecular structures and van der Waals forces
• What are the molecular forms of phosphorus, sulfur, and chlorine?

  P4, S8, and Cl2 respectively
• What type of forces exist between the molecules of phosphorus, sulfur, and chlorine?

  Van der Waals forces
• How does the size of a molecule affect van der Waals forces?

  Larger molecules have stronger van der Waals forces
• Why does chlorine have a lower melting point than sulfur and phosphorus?

  Chlorine is a smaller molecule
• What type of bonding does argon exhibit?

  Monatomic with weak van der Waals forces
• Why does argon have a lower melting and boiling point than chlorine?

  Argon has only single atoms
• What are the key points regarding melting and boiling points across the period?

  • Metallic bonding increases melting/boiling points
  • Silicon has strong covalent bonds, high melting/boiling points
  • Phosphorus, sulfur, chlorine have lower points due to simple molecular structures
  • Argon has very weak van der Waals forces, lowest points
• What is the expected knowledge regarding phosphorus, sulfur, and chlorine's molecular forms?

  Know P4, S8, and Cl2 forms
• How do the melting and boiling points of sodium, magnesium, and aluminium compare?

  They increase across the period
• What is the trend in melting and boiling points from silicon to argon?

  They generally decrease across this range