T1W6L3

electronegativity revision §

• ${}^{\delta +}H:\to F^{\delta -}$
  • bond polar? yes
  • molecule polar? yes
• ${}^{\delta -}O=C^{\delta +}=O^{\delta -}$
  • molecular non-polar
• ${}^{\delta +}H-S^{\delta -}-H^{\delta +}$ (pretend this is non symmetrical in the shape of / \)

  what is going on?! study in your own time please future thomas

ionisation energy §

• required to remove an electron.

• there is an attraction between electron and nucleus.

• there could be multiple ionisation energy, first second third blah blah blah

• first ionisation energy §

  • the first ionisation is the energy required to remove one mole of electrons from one mole of gaseous atoms.

  • for unknown elements for unknown element M, the equation goes as follows: $M(g)\to M^{+}(g)+e^{-}$

  • ionisation energy is a measurement to the reactivity of metals.

  • when metals react they lose electrons (removed) which takes ionisation energy.

  • G1 only needs the first ionisation energy, for group 2 you need first & second ionisation energy.

  • trends of first ionisation energies of the group 2 elements.

    • ionisation energy has a general decrease as you move down through groups of elements.

  • trends of first ionisation energy of the period 3 elements

    • nuclear attraction increases
    • atomic radius decreases
    • atomic number (proton number) increases
    • there is a general increase in the first ionisation energies across period 3.
    • shielding does not change significantly.
    • effective nuclear charge therefore increases.
    • the greater attraction between nucleus and the outermost electrons means more energy is required to remove an electron.

  • EXTENSION: why sulfur and aluminium has lower first ionisation energies.

    • Mg: 2,8,2

    • Al: 2,8,3

    • 1s22s22p63s2

    • 1s22s22p63s23p1

    • Phosphor

      • 15-10 = 5
      • 2,8,5
      • 1s22s22p63s23p3

    • Sulfur

      • 16 - 10 = 6
      • 2,8,6
      • 1s22s22p63s23p4