First Children Encyclopedia

219 A closer look During the 17th century, the microscope was developed by Dutchman Anton van Leeuwenhoek and refined by Robert ...

220 Science and everyday life What was the first satellite in space? Science and technology Cities at night are bright places, l ...

221 Science and everyday life 221 As^ fast^ as^ a^ s peeding^ bullet^ tr ain...? Sputnik 1. It was launched by the Soviet Union ...

222 Every living thing contains carbon. Human beings take in carbon through carbohydrates, fats, and proteins in food, and relea ...

223 DigestersDecomposition in the soil is helped along by the endless action of worms and bacteria. These animals are an importa ...

224 Some materials are hard and brittle, while others are flexible. Some materials are colourful, while others are transparent. ...

225 Brittleness Some materials, such as glass, are very brittle and will break when pushed out of shape. Safety glass is designe ...

226 When solids get hot enough, they melt and become liquids. When liquids get cold enough, they freeze and become solid. This i ...

227 Freezing Icicles are spikes of ice that form when dripping water freezes. You often see them on trees in winter. If water ke ...

228 Amazing atoms E l e c t r o n s w h iz z^ around (^) t he (^) nu c l e u s o f^ th e at om If you could keep smashing an obj ...

229 The mighty atom When the nucleus of an atom is split, it releases a huge amount of energy. Nuclear bombs use this “atomic en ...

230 In most materials, atoms are joined in tiny groups called molecules. The shapes of molecules and the way they pack together ...

231 Diamond molecule Diamond is the hardest natural substance known. Its hardness comes from the way the carbon atoms in each di ...

232 When the atoms in molecules rearrange to form new kinds of molecules, we say a chemical reaction has taken place. Chemical r ...

233 Soda volcano If you drop mints into a bottle of fizzy drink, the drink turns to foam and explodes out in an instant. This is ...

234 Energy is what makes everything happen. Your body needs energy so that you can move, grow, and keep warm. We also need energ ...

235 Electrical energy Lightning is caused by electrical energy in a storm cloud. The electrical energy turns into the heat and l ...

236 Have you ever thought about what powers your television, your computer, or the lights in your bedroom? A flow of electricity ...

237 Electricity A battery. Circuits of power An electric circuit is a loop that electricity can travel around. An electric curre ...

238 Light is a form of energy that our eyes can detect. It comes in all the colours of the rainbow, but when the colours are mix ...