Page 3 - CBW
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12. a) Why are gaps left between railway tracks,
and how do they prevent damage to the
tracks?
b) What might happen if the gaps were not
provided? Discuss the potential
consequences.
13. You place a piece of iron in a moist environment. Over time, the iron develops a reddish-
brown coating, indicating rust formation.
Questions:
a) What type of change is rusting of iron: physical or chemical? Justify your answer.
b) What measures can be taken to prevent rusting of iron? Discuss at least two methods.
14. What is the role of heat in causing changes? Provide an example.
15. Give one example in which physical and chemical changes occur simultaneously.
