DP Chemistry (last assessment 2024)
Question 19M.3.sl.TZ1.12a(ii)
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.3.sl.TZ1.12a(ii) |
| Level | sl | Paper | 3 | Time zone | TZ1 |
| Command term | Outline | Question number | a(ii) | Adapted from | N/A |
a(ii).
[Maximum mark: 1]
19M.3.sl.TZ1.12a(ii)
Uranium-235, 235U, is bombarded with a neutron causing a fission reaction.
Two products of the fission of 235U are 144Ba and 89Kr.
(a(ii))
Outline why the reaction releases energy.
[1]
Markscheme
greater binding energy per nucleon in products than reactant [✔]
Note: Accept “mass of products less than reactants” OR “mass converted to energy/E = mc2”.
Examiners report
Only about a quarter of the candidates could explain the release of energy, usually in terms of the change in nuclear binding energy.
