DP Physics (first assessment 2025)
Question 19M.2.SL.TZ2.b
| Date | May 2019 | Marks available | [Maximum mark: 3] | Reference code | 19M.2.SL.TZ2.b |
| Level | SL | Paper | 2 | Time zone | TZ2 |
| Command term | Explain | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 3]
19M.2.SL.TZ2.b
Explain why some of this radiation is returned to the oceans from the atmosphere.
[3]
Markscheme
«most of the radiation emitted by the oceans is in the» infrared ✔
«this radiation is» absorbed by greenhouse gases/named greenhouse gas in the atmosphere ✔
«the gases» reradiate/re-emit ✔
partly back towards oceans/in all directions/awareness that radiation in other directions is also present ✔
Examiners report
For many this was a well-rehearsed answer which succinctly scored full marks. For others too many vague terms were used. There was much talk about energy being trapped or reflected and the ozone layer was often included. The word ‘albedo’ was often written down with no indication of what it means and ‘the albedo effect also featured.
