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Elements

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  Elements in groups and periods There are just about 120 known components. For instance, you are comprised of billions of billions of particles yet you . Elements CHEMICAL ELEMENTS ARE those substances that cannot be split up into other substances. For example, gold cannot be split but water can be split into the elements hydrogen and oxygen. Each element is made up of atoms with fixed number of protons in their nucleus. Atoms of gold have 79 protons in their nucleus while atoms of hydrogen have 1.- Elements in groups and periods Number of elements There are about 85 naturally occurring elements. But scientists have discovered about 25 more, making the total number of identified Elements in groups and periods is , 112. Periodic table Periodic table is a chat devised by John Dalton (1766-1844) on which all the elements can be arranged according to the number of protons in the nucleus. The columns in the table are called Groups, and the rows are called Periods. Each period

Tiny Wonders

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Tiny Wonders What is an Atom?   ATOMS ARE THE VERY SMALL BITS or particles of the thing of which any substance is made. They are too small to be seen. Two billion atoms would fit on the dot that is on the top of this 'i'. Scientists earlier thought atoms were the tiniest things in the universe, like hard balls that could never be split or destroyed. But now, they know that atoms are more like clouds of energy, mostly empty space, containing even tinier sub-atomic' particles. Inside an atom At the center of every atom, there is a dense core or 'nucleus' having two kinds of tiny particles protons and neutrons. Around the nucleus, there are even tinier particles called electrons that move around at the speed of light. Size of atoms Atoms weigh about 100 trillionths of a trillionth of a gram and are about a ten-millionth of a millimeter big. The smallest atoms are the hydrogen atoms. Helium nucleus One of the smallest nuclei of an atom is that of an at

Solid liquid and gas

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  Solid-liquid and gas Freezing On cooling, the molecules in the liquid slow down for forming regular bonds between them. Thus, lovely crystals form, when water freezes to snowflakes. What is Matter? MATTER IS EVERYTHING AROUND US. Any substance in the universe that takes up space is known as matter. The matter is found in three different forms or states in solid form, like a brick, in liquid forms, like water, and in the form of gas, like air. At the right temperature and pressure, any substance can change its form and reverse again. For example, the liquid, water, turns into ice and ice turns into water. Solid A strong substance that has a definite shape is solid. Every substance is made from very tiny bits called molecules. Molecules are so small that   they cannot be seen. In a solid substance, the molecules are bonded together firmly in a regular structure. All molecules keep moving all the time, but molecules simply vibrate on the spot in a solid. AS it gets

Earth-the Wonder Planet

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Earth-the Wonder Planet What is Earth? The earth is one of the eight planets that continually revolve around the sun. The planets and the Sun make our solar system. The Earth is the third planet out from the Sun, located between Venus and Mars. The Earth is a sphere made largely of rock. Two-thirds of the surface is covered by water. It is the only planet with oxygen in its atmosphere. The presence of water and oxygen is what makes the Earth a suitable planet for the existence of life. How did the Earth begin?   The Earth was a clouds of gases and dust that circled around the sun about four and a half billion years ago. Then the clouds of gas started to condense and thus formed trillions of small beads. These beads then started to clump together as a single mass due to gravity. This mass is now we live on. Thus the Earth was just a ball of fire a long ago and later it got its hard crust and atmosphere due to gradual Cooling. How were the planets formed?   No-one is absolutely sure how

Earth Shudders

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  Earth Shudders What is an earthquake? An earthquake is the shaking of the ground. Some earthquakes are so mild that they go unnoticed but some are so violent they can shake down mountains and destroy cities. Many things can set off small earthquake from the rumbling of heavy traffic to the eruption of a volcano. But the biggest earthquakes are set off by the trembling of the tectonic plates that make up the Earth's surface as they grind slowly together underground . What causes earthquakes? The tectonic plates are sliding past each other all the time but sometimes they jam. Then the rock bands and stretches for a while until the strain gets so much that it snaps and the plates lurch on again. The snapping or the rock and sudden jolting of the plates sends shock waves out in all directions. When these waves reach the surface, they create earthquakes.   What is focus and epicenter? The starting point of an earthquake inside the Earth is called the hypocenter or focus.

Mountain Range

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  Mountain Range The Himalayas Peaks kie K2 (8,611 m), Kanchenjunga (8,598 m), Lhotse (8,511 m) and Everest (8,848 m) are found in the Himalayas.   What are the world's highest mountains? The world's highest mountains are the Himalayas in Asia to the north of India. The world's ten tallest mountains are found here, including the Mount Everest. It is 8,848 m high. But the other continents too have their high mountain ranges. The Andes are in South America, where there are many peaks over 6,000 m; the Rocky Mountains in North America and the Alps in Europe. What is the period of mountain formation? Mountains are being created all the time-although if takes many millions of years. Most of the world's highest mountains were formed quite recently. The Himalayas have formed within the last 40 million years –and they are growing even today . How do mountains form? Some mountains are created by volcanic eruptions. But most mountains are thrown up by the tremen

Earth Crust

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  Earth Crust What lies within the Earth? The Earth gets hotter and hotter. The temperature reaches, 7000 0 C hotter than of the surface of the sun. Thus, just beneath the crust is the layer of half-molten rocks thousands of kilometers deep called the mantle. Within the earth center is the core. The outer core is made of molten iron and nickel. In the inner core, the Pressure is intense, therefore, despite being so hot, it is solid. Can anyone visit the Earth's center? It is not possible. No one has ever managed to drill more than 12 km down. Even at this depth, pleasure, are so great and the rock is so hot and soft that the drill bores close up as fast as they are drilled. What is the composition of the mantle? The mantle is made of rock like the crust. But the most common minerals here are minerals that are rare on the surface, like perovskite and olivine. How do scientists hear the Earth's interior? The vibrations of the earthquakes help us in that. Long aft