Why are frozen things so hard?
Most of our everyday world is frozen solid, even in the sweltering heat of summer. Your bike, your tv set, the house in which you live are solid objects, because they are cool enough to freeze to a solid state. But if you put most of these things into a blast furnace, they would melt to runny liquids and finally become gases and boil away. The day’s weather may dip down below zero or rise above 90 degrees. The seas and the dry land, the air and everything around us feels the sun’s heat which falls upon the face of our world. And all these things which make up our world are made from particles of matter too small for our eyes to see. We call them atoms and molecules. Atoms and molecules are restless particles, always eager to move around. They get their energy from heat the more heat they get, the faster they move. Oxygen gets enough heat from everyday temperature to fly off as separate molecules of gas. When you put an iron poker into a furnace at 1539 degrees centigrade, its atoms get
