Periodicity

• What block do Groups 1 and 2 belong to in the periodic table?

  s block
• What block do the transition metals belong to?

  d block
• Where is the p block located on the periodic table?

  Right hand side
• In which block are the actinides and lanthanides found?

  f block
• What does a group of elements in the periodic table signify?

  Similar chemical properties and same outer electrons
• What trend is observed in melting and boiling points across period 3?

  Giant structures have high melting points, as you go from left to right the charge on the ion increases so more electrons join the delocalised 'sea' of electrons, increasing strength of metallic bonds
• Why do molecular and atomic structures have low melting and boiling points?

  Depends on size of van der Waals forces
• Why does sulfur have a higher melting point than phosphorus?

  It is a bigger molecule
• What type of structure does silicon have?

  Giant covalent structure, you have to break strong covalent bonds in order to melt it
• Why do atomic radii decrease across a period?

  More protons added, no extra electron shells so there is no extra shielding effect
• Why do atomic radii increase going down a group?

  Atoms gain an extra shell of electrons, so going down a group the outer electron main level gets further from the nucleus and the radii increases
• Why does the first ionisation energy increase across a period?

  More protons, same number of electron shells
• Why does the first ionisation energy decrease going down a group?

  Increased shielding effect and atomic radius
• Why is there a drop in ionisation energy from one period to the next?

  Extra electron shell increases atomic radius
• Why is there a drop in first ionisation energy between magnesium and aluminium?

  Aluminium's electron is in a higher energy level
• Why is there a drop in first ionisation energy between phosphorus and sulfur?

  Electron pair repulsion in sulfur's outer shell
• What group is indicated by the successive ionisation energies: 906, 1 763, 14 855, 21 013?

  Group 2
• What does the jump in successive ionisation energies indicate?

  Indicates the removal of an electron from a new shell