S1.3 Electron configurations (SL)
15 revision questions with answers for S1.3 Electron configurations (SL). Read them here, or play the set as a class game on the projector. Free to host, and students join with a code.
Bright lines on a black background, produced as excited electrons fall to lower levels?
- Absorption spectrum
- Continuous spectrum
- Mass spectrum
- Emission spectrumRight answer
What this set covers
Emission spectra and the Bohr picture of hydrogen lead into sublevel capacities, the three filling rules and full configurations for atoms and ions, including the chromium exception and Fe²⁺.
- Common mix-up
- Students often mix up Hund's rule and the Pauli exclusion principle: one is about filling degenerate orbitals singly first, the other about two opposite spins per orbital.
- Revision tip
- Write the configurations of iron, chromium and Fe²⁺ on a blank page, then draw the orbital boxes for nitrogen to see why it has three unpaired electrons.
All 15 questions and answers
Bright lines on a black background, produced as excited electrons fall to lower levels?
Answer: Emission spectrum
In hydrogen's spectrum, lines get closer together at higher energy until they…?
Answer: Converge
Visible lines in hydrogen's spectrum come from transitions down to which level?
Answer: n = 2
Transitions down to n = 1 in hydrogen emit radiation in which region?
Answer: Ultraviolet
A higher-energy photon has a higher frequency and a shorter…?
Answer: Wavelength
Maximum number of electrons in a d sublevel?
Answer: 10
Maximum number of electrons in the n = 3 energy level?
Answer: 18
Rule that an orbital holds at most two electrons, with opposite spins?
Answer: Pauli exclusion principle
Electrons occupy degenerate orbitals singly, spins parallel, before pairing: this is…?
Answer: Hund's rule
Filling orbitals in order of increasing energy follows the…?
Answer: Aufbau principle
Sublevel filled immediately after 4s?
Answer: 3d
Unpaired electrons in a ground-state nitrogen atom?
Answer: 3
Condensed electron configuration of iron (Z = 26)?
Answer: [Ar] 3d⁶ 4s²
Condensed electron configuration of chromium (Z = 24)?
Answer: [Ar] 3d⁵ 4s¹
Electron configuration of the Fe²⁺ ion (Z = 26)?
Answer: [Ar] 3d⁶
Play it as a class game
Play this set opens it in splycr, where you can host it for your class straight away. Hosting needs no account: put the room code on the projector, and students join from a phone with the code and their first name. Each question plays as multiple choice, and the three wrong options were written for that question.