Question 21N.2.hl.TZ0.b(iii)
| Date | November 2021 | Marks available | [Maximum mark: 3] | Reference code | 21N.2.hl.TZ0.b(iii) |
| Level | hl | Paper | 2 | Time zone | TZ0 |
| Command term | Explain | Question number | b(iii) | Adapted from | N/A |
Fast moving helium nuclei (4He2+) were fired at a thin piece of gold foil with most passing undeflected but a few deviating largely from their path. The diagram illustrates this historic experiment.
Figure from PPLATO / FLAP (Flexible Learning Approach To Physics), http://www.met.reading.ac.uk/pplato2/h-flap/
phys8_1.html#top 1996 The Open University and The University of Reading.
Copper is a transition metal that forms different coloured complexes. A complex [Cu(H2O)6]2+ (aq) changes colour when excess Cl− (aq) is added.
Explain the cause of this colour change, using sections 3 and 15 from the data booklet.
[3]
chloride is lower in the spectrochemical series ✔
«ligand cause» decreased/lesser splitting «in d-orbitals compared to H2O» ✔
frequency/energy of light absorbed is decreased
OR
wavelength of light absorbed is increased ✔
Accept ·chloride a weaker ligand than water/produces a smaller energy difference than water for M1.
Award [2 max] for mentioning splitting of orbitals is changed AND frequency/ wavelength/energy of light absorbed
are different/changed without mentioning correct decrease or increase.
