User interface language: English | Español

Date November 2018 Marks available 2 Reference code 18N.2.sl.TZ0.4
Level SL Paper 2 Time zone TZ0
Command term Explain Question number 4 Adapted from N/A

Question

Properties of elements and their compounds can be related to the position of the elements in the periodic table.

Explain the decrease in atomic radius from Na to Cl.

[2]
a.

Explain why the radius of the sodium ion, Na+, is smaller than the radius of the oxide ion, O2−.

[2]
b.i.

State a physical property of sodium oxide.

[1]
b.ii.

Markscheme

nuclear charge/number of protons/Zeff increases «causing a stronger pull on the outer electrons» ✔

same number of shells/«outer» energy level/shielding ✔

 

Accept “atomic number” for “number of protons”.

a.

isoelectronic/same electronic configuration/«both» have 2.8 ✔

more protons in Na+

b.i.

Any one of:
brittle ✔
high melting point/crystalline/solid «at room temperature» ✔
low volatility ✔
conducts electricity when molten ✔
does not conduct electricity at room temperature ✔

 

Do not accept soluble in water.

Ignore any chemical properties.

b.ii.

Examiners report

[N/A]
a.
[N/A]
b.i.
[N/A]
b.ii.

Syllabus sections

Core » Topic 3: Periodicity » 3.2 Periodic trends
Show 78 related questions
Core » Topic 3: Periodicity
Core

View options