Important Questions on Changes Around us Give two examples of physical changes that are irreversible. Distinguish between reversible and irreversible changes. Give examples. Write some examples of expansion in solids, liquids and gases. How is contraction different from expansion? Explain with an example. List any three real-life applications of expansion and contraction of substances. Explain how an iron blade is fixed onto a wooden handle to be used as a tool for digging soil. When you light a candle, the wick burns and the wax melts. Are these two changes similar? Explain. (Hint: Recall the concept of physical and chemical changes) You must have noticed your mother struggling with steel vessels that get stuck with one another. How will you help her to separate the vessels? 
