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Aitchison College Academic Resources.
a
3 This question is about ionic and covalent compounds.
(a) (i) Sodium reacts with oxygen to form the ionic compound sodium oxide.
The electronic configurations of an atom of sodium and an atom of oxygen are shown in
Fig. 3.1.
sodium atom oxygen atom
Fig. 3.1
lons are formed by the transfer of electrons from sodium atoms to oxygen atoms.
Complete the dot-and-cross diagrams in Fig. 3.2 to show the electronic configuration of
one sodium ion and one oxide ion. Show the charges on the ions.
sodium ion oxide ion
©
Fig. 3.2
[3]
(ii) Write the formula of sodium oxide.
[1]
(b) Carbon dioxide, CO,, is a covalent compound.
Complete the dot-and-cross diagram in Fig. 3.3 to show the electronic configuration in a
molecule of carbon dioxide. Show outer shell electrons only.
tf
Fig. 3.3
[2]
@UCLES 2023 0620/4 1/23
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