DP Chemistry (last assessment 2024)
Question 19M.3.hl.TZ1.d(i)
| Date | May 2019 | Marks available | [Maximum mark: 1] | Reference code | 19M.3.hl.TZ1.d(i) |
| Level | hl | Paper | 3 | Time zone | TZ1 |
| Command term | Describe | Question number | d(i) | Adapted from | N/A |
d(i).
[Maximum mark: 1]
19M.3.hl.TZ1.d(i)
Lithium has many uses.
Lithium has shown some superconductive properties when doped into graphene or when under high pressure. Under high pressure, however, the Meissner effect is absent.
Describe the Meissner effect.
[1]
Markscheme
creation of mirror image/opposing magnetic field of external field «below critical temperature/T of superconductor»
OR
expulsion of magnetic field from superconductor «below critical temperature/T» [✔]
Examiners report
Candidates had some difficulty describing the Meissner effect, with several responses using the terms repelling or repulsion instead of opposing and expulsion. Correct terminology is required.
