DP Chemistry (last assessment 2024)
Question 19M.3.hl.TZ2.20a
| Date | May 2019 | Marks available | [Maximum mark: 2] | Reference code | 19M.3.hl.TZ2.20a |
| Level | hl | Paper | 3 | Time zone | TZ2 |
| Command term | Sketch | Question number | a | Adapted from | N/A |
a.
[Maximum mark: 2]
19M.3.hl.TZ2.20a
Semiconductors and light-sensitive dyes are used in photovoltaic cells.
(a)
Sketch graphs to show the general effect of increasing temperature on the electrical conductivity of semiconductors and metals on the axes below.
[2]
Markscheme
Semiconductors:
increases [✔]
Metals:
decreases [✔]
Note: Accept any graph showing general increase for semiconductor.
Accept any graph showing general decrease for metal.
Accept a graph showing vertical section below transition temperature for a superconducting metal.
Examiners report
Several candidates managed one mark to show conductivity of semiconductors on increasing the temperature but were unable to show that generally conductivity decreases for metals when the temperature is increased.
