IB Chemistry SL 3.1.3 Periodicity Questions

Use real exam questions to identify and explain how the listed periodic properties change across periods and down groups.

Exam points

Identify and compare the direction of atomic radius, ionic radius, first ionization energy, electron affinity and electronegativity across periods and down groups.
Explain periodic-trend directions using nuclear charge, shielding, occupied energy levels, sublevel energy and electron-pair repulsion.
Apply periodic-trend evidence to rank atoms or ions and justify a stated prediction about radius, ionization energy, electron affinity or electronegativity.

Learn this topic

Study 3.1.3—Periodicity conceptsOpen the corresponding Concept lesson for explanations, examples and exam connections.

[Maximum number: 3]

Chlorine undergoes many reactions.

(a)

State, giving a reason, whether the chlorine atom or the chloride ion has a larger radius.

[ 1 ]

$\mathrm{Cl}^{-}$ AND more «electron-electron» repulsion

Marking guidance:

Accept $\mathrm{Cl}^{-}$ AND has an extra electron.

(b)

Outline why the chlorine atom has a smaller atomic radius than the sulfur atom.

[ 2 ]

Cl has a greater nuclear charge/number of protons/ $\mathrm{Z}_{\text {eff }}$ «causing a stronger pull on the outer electrons»

same number of shells

OR

same «outer» energy level

OR

similar shielding

All question bank results loaded

Learn this topic

IB Chemistry SL 3.1.3 Periodicity Questions question 1

Question (a)

Question (b)