EL1 - EL5

• Speed of light = 3.00 x 10^8
• Speed of light = frequency x wavelength
• Energy of a photon = Planck's constant x frequency
• Dip a platinum wire loop into hydrochloric acid. Then place into solution. Then place over a roaring blue flame. Observe and write down the colour.
• Li+ = bright red

  Na+ = yellow

  K+ = lilac

  Ca2+ = brick red

  Ba2+ = apple green

  Cu2+ = blue green
• s = 1 orbital , max 2 electrons.

  p = 3 orbitals, max 6 electrons.

  d = 5 orbitals, max 10 electrons.

  f = 7 orbital, max 14 electrons.
• 3d have more energy than 4s.
• VSEPR = Valence Shell Electron Pair Repulsion
• Maximum repulsion between 2 = 180 degrees (linear)

  3 = 120 degrees (trigonal planar)

  4 = 109.5 degrees (tetrahedral)

  5 = 90, 120, 180 degrees (trigonal bipyramid)

  6 = 90, 180 degrees (octahedral)
• Each lone pair reduces the bond angle by 2.5 degrees.
• 2 bonds, 1 lone = V-shaped/bent (120 - 2.5 = 117.5 degrees)

  3 bonds, 1 lone = trigonal pyramid (109.5 - 2.5 = 107 degrees)

  2 bonds, 2 lone = V-shaped/bent (109.5 - 5 = 104.5 degrees)
• 4 bonding groups and 1 lone pair = seesaw (no reduce of angle).

  3 bonding groups and 2 lone pairs = T-shape (no reduce of angle).

  2 bonding groups and 3 lone pairs = linear (no reduce of angle).

  5 bonding groups and 1 lone pair = square pyramid (no reduce of angle).

  4 bonding groups and 2 lone pairs = square planar (no reduce of angle).

  3 bonding groups and 3 lone pairs = T-shape (no reduce of angle).

  2 bonding groups and 4 lone pairs = linear (no reduce of angle).