Question

This question is about chemical bonding.
(a) Put a tick (3) in the box next to the sentence that describes a metal atom.   
An atom that gains electrons to get a full outer shell and become stable.   
An atom that shares electrons to get a full outer shell and become stable   
An atom that loses electrons to get a full outer shell and become stable.     

(b) Complete the sentences about ionic bonding.
Choose words from the list.
Each word can be used once, more than once or not at all.
             chlorine                opposite          similar
             lattice                    oxygen            sodium
             molecular             polymer           strong
            negative                positive            weak

If an atom gains electrons a ……………………………… ion is formed.
An example of an atom gaining 1 electron to complete its outer shell is …………………………… .
During the formation of ionic bonds there is a ……………………………… attraction between
ions because of their ……………………………… electrical charges. The ions form a regular
arrangement of alternating ions called a ……………………………… structure.

(c) (i) Fig. 5.1 shows the bonding in a molecule of water, H₂O.

State the name of the type of bonding in a molecule of water.

(ii) Complete the dot‐and‐cross diagram in Fig. 5.2 to show the bonding in a molecule of nitrogen, N₂.

You only need to show the outer‐shell electrons.

(iii) Water and nitrogen have low melting points.
Explain why in terms of attractive forces. 

▶️Answer/Explanation

Ans : 5(a) an atom that gains electrons to get a full outer shell and become stable.     

an atom that shares electrons to get a full outer shell and become stable.                               

an atom that loses electrons to get a full outer shell and become stable.                       

5(b) negative ;
chlorine ;
strong ;
opposite ;
lattice ;

5(c)(i) covalent ; 
5(c)(ii)     

5(c)(iii) (water and nitrogen) have weak intermolecular forces / weak attractions between molecules ;

idea that (weak intermolecular forces) take little energy to break ;