1. In terms of structure and bonding, explain why graphite is used as a lubricant in machines. (3 marks)
2. Element U has atomic number 12 while element V has atomic number 16. How do the melting points of their oxides compare? Explain. (3 marks)
3. Table 1 shows the properties of two chlorides, D and E.

Chloride	Melting Points(°C)	Electrical Conductivity(liquid)
D	1074	Good
E	203	Poor

(a) State the type of bond present in:
(i) D.......................(1 mark)
(ii) E.......................(1 mark)
(b) Explain in terms of structure and bonding, the difference in electrical activity of the chlorides D and E. (1 mark)

lonic band -NaCl O TYPES OF CHEMICAL BONDS Metallic bond metallic sodium Na Na Covalent bond - H2 Hydrogen bond solid HO