DP Chemistry (first assessment 2025)
Question 21N.2.SL.TZ0.2b
| Date | November 2021 | Marks available | [Maximum mark: 1] | Reference code | 21N.2.SL.TZ0.2b |
| Level | SL | Paper | 2 | Time zone | TZ0 |
| Command term | Calculate | Question number | b | Adapted from | N/A |
b.
[Maximum mark: 1]
21N.2.SL.TZ0.2b
(b)
Sodium emits yellow light with a frequency of 5.09 × 1014 Hz when electrons transition from 3p to 3s orbitals.
Calculate the energy difference, in J, between these two orbitals using sections 1 and 2 of the data booklet.
Darling, D, n.d. D lines (of sodium). [online] Available at <https://www.daviddarling.info/encyclopedia/D/D_lines.html> [Accessed 6 May 2020].
[1]
Markscheme
«ΔE = hν = 6.63 × 10–34 J s × 5.09 × 1014 s–1 =» 3.37 × 10–19 «J» ✔
Syllabus sections
Structure 1. Models of the particulate nature of matter » Structure 1.3—Electron configurations » Structure 1.3.1—Emission spectra. Emission spectra are produced by atoms emitting photons when electrons in excited states return to lower energy levels. Qualitatively describe the relationship between colour, wavelength, frequency and energy across the electromagnetic spectrum. Distinguish between a continuous and a line spectrum.