DP Chemistry (first assessment 2025)
Question 22N.1A.HL.TZ0.6
| Date | November 2022 | Marks available | [Maximum mark: 1] | Reference code | 22N.1A.HL.TZ0.6 |
| Level | HL | Paper | 1A | Time zone | TZ0 |
| Command term | State | Question number | 6 | Adapted from | N/A |
6.
[Maximum mark: 1]
22N.1A.HL.TZ0.6
Which best explains why complexes of d-block elements are coloured?
A. Light is absorbed when electrons are promoted between d orbitals.
B. Light is emitted when electrons are promoted between d orbitals.
C. Light is absorbed when electrons return to lower energy d orbitals.
D. Light is emitted when electrons return to lower energy d orbitals.
[1]
Markscheme
A
Examiners report
About 70% of candidates selected the best explanation for the colour of d-block elements. The most commonly chosen distractor (D) indicates that a significant number of students believe that the elements emit light.
Syllabus sections
Structure 3. Classification of matter » Structure 3.1—The periodic table: Classification of elements » Structure 3.1.8—Transition elements have incomplete d-sublevels that give them characteristic properties. Recognize properties, including: variable oxidation state, high melting points, magnetic properties, catalytic properties, formation of coloured compounds and formation of complex ions with ligands.