How does a thermometer work? The hotter a substance, the faster its molecules move taking up more space. The thermometer has a liquid that expands as it gets heated up. Then the level of liquid rises in a narrow tube. A scale beside the tube...
Why is gold so costly? Gold is not only beautiful but it is also rare. This soft yellow metal is one of the heaviest chemical elements. Gold does not tarnish when exposed to air. This is probably one reason why people value it so highly....
What is the Dead Sea? The Dead Sea is a large, narrow salt lake that lies between Jordan and Israel. It is the lowest area of water ever found in the world and its surface is about 400 m below sea level. The Dead Sea...
What is a bloodhound? The bloodhound is a type of dog that was bred for its keen scent. It is probably descended from a dog called `St. Hubert.’ Bloodhounds have a keener sense of scent than other dogs. They are also persistent and these two...
How do animals survive in the desert? There is very little water in the desert. Animals which live in the desert make optimum use of the available water. Some live in underground burrows to escape the heat during daytime. They come out at night when...
Why do soldiers salute? Salutes are quite old, in fact. People salute to show their respect to someone of a higher rank. Salutes come in many forms. Some people even salute lying on the ground. The modern soldier’s salute was born at the end of...
Who invented the computer? It was a British man called Charles Babbage who invented the first computer in 1834. It was the first mechanical computer that could be programmed. But he lacked money to build it. He didn’t have the technology either. It was only...
Why did pyramids have temples in them? Religion played an important role in the lives of Egyptians. Temples were considered to be the gods’ homes on earth. Special ceremonies were conducted before and after pharaohs were placed in their tombs. For this reason, pyramids had...
What causes volcanoes? Volcanoes occur along fault lines. Molten rock and gases are pushed out with great force through an opening in the earth’s crust to release pressure. After many years, cooled rocks build up around the opening in the ground to form a conical...
Where did the Romans relax? The Romans relaxed by going to the public baths. They were actually like recreation centres. Here they could play games, read, talk to friends and exercise in the gym or walk around in the gardens. They could even get haircuts...
