It is not easy to define what a metal is. Physically, a metal is a substance that has a bright luster and is a good conductor of heat and electricity. Metals have varying degrees of hardness, density, malleability and ductility. (Malleability concerns being able to be rolled Out and hammered. Ductility has to do with … Read more

All material things on earth are made up of one or more elements. Elements are substances that have atoms of only one kind.Any one element may have some of the same properties that other elements have, but no two elements are exactly alike. For example, hydrogen and helium are colorless, odorless, and tasteless gases. They … Read more

Air is everywhere about you. Every crack, hole and space that is not already filled with something else is filled with air. Every time you breathe, your lungs are filled with air. Even though you cannot see air, nor taste it, nor feel it (unless the wind is blowing), air is "something". It is a … Read more

A molecule is the smallest particle of a substance that can exist and still keep the properties of the whole. For example, if you broke down a molecule of sugar, the elements would not have the characteristics of sugar—its taste or its color, among other things. Sometimes molecules are very simple; others have thousands of … Read more

Ice is a solid. When the temperature is cold enough, liquid 'water becomes solid ice. Water expands greatly when it freezes. Ten !intercrop water make about 11 liters of solid ice. Objects in water float or sink acaccording to' a principle that was first discovered by Archimedes, a Greek mathematician who lived in the third … Read more

Force" is a push or a pull which changes the motion, or movement, of objects. When you push a chair, you are exerting force on it. When you stop pushing, the chair stops moving. But suppose you roll a ball along the ground. It keeps on rolling after you have stopped pushing it! Why? The … Read more

If it were harnessed, as it is from waterfalls and rivers, the power could be enormous. The French have pioneered this form of tidal power in their huge hydroelectric project near St. Malo in Brittany. Nestling at the foot of the Cotentin peninsula between Dinard and St. Malo, it is able to take advantage of … Read more

Talc is a mineral—the softest mineral known to man. It can be scratched easily with the fingernail. It is made of tiny flakes, or scales, of magnesium. Talc may be silvery white or even a delicate green. When talc is in solid form it is called "soapstone". In this form it is usually greyish or … Read more

It can be drawn out into wires that are finer than the finest hairs, and hammered into sheets as thin as a sheet of newspaper. It may surprise you to learn that it is the most abundant of an the metals in the world. Nearly 8 per cent of the earth's crust is Aluminum. But … Read more

It is the hard rock that forms much of the earth's outer crust. The name "granite" comes from the Latin word gramim, meaning" grain". The grains in granite are crystals of quartz, feldspar, mica, and hornblende.Granite varies in colour. It may be greyish or pinkish and it may also be coloured by impurities.Granite is one … Read more

Dust consists of tiny particles of solid matter that can be carried in suspension by air. Dust is usually lifted by the wind from the place it originated and is canied along by air currents until it finally settles,because of gravity, or it comes down with rain. Dust is produced by a wide range of … Read more

Carbon is important to all forms of life. It makes up less than 1 per cent of all matter, but everything that lives or has lived contains this element. The bodies of all living things are made up of compounds containing Carbon, and where it is found in any quantity in the earth, life has … Read more

Basically, a diamond is a beautiful gem. So we might say that its beauty makes it desirable and valuable. The diamond is also the hardest substance known to man, and this hardness is very useful. So this also makes.         The diamond valuable. Now why should one diamond be more valuable  than  … Read more

The great Ice Age, or Glacial Period, was a time when a great mass- of ice came down gradually from the north and covered parts of the world. It came down over North America, and a similar mass of ice came down over northern Europe and western Siberia. When did this happen? It is thought … Read more

In 1856, the remains of men were dug from a limestone cave in the Neanderthal Gorge in Germany. These were the first complete skeletons ever found of prehistoric men, and this was because these people buried their dead. Neanderthal people probably lived for about 70,000 years in central Asia, the Middle East, and many parts … Read more

All over the world, there are people who are waging "conservation" campaigns. Conservation means many things to many people.To some it means preserving the wilderness in certain sections. To others it means preserving the wildlife. Conservation includes efforts to protect forests, as well as the wise use of all natural resources. The problem of conservation … Read more

Deserts have come to symbolize for us places of extreme heat. The fact is, most of the famous deserts of the world are places where the thermometer goes bubbling away and where the sun beats down without mercy. But this does not mean that a desert must be a place where it is always hot. … Read more

The outside of the earth is a crust of rock which is about 10 to 30 miles thick. When we go down into this crust, we find that it begins to get hotter and hotter. For about every 40 meters we go down, the temperature grows one degree higher. At two miles below the surface … Read more

People who live in the city do not have to worry about wells or springs. The city supplies them with water. But out in the country and in some suburbs, obtaining a water supply may be quite a problem. Such water may come from a spring or a well. A spring is water that flows … Read more

In February, 1943, in the middle of a cornfield in Mexico, people saw a rare and amazing thing taking place. A volcano was being born! In three months it had formed a cone about 300 meters high. Two towns were destroyed and a wide area damaged by the felling ash and cinders. The temperature Under … Read more