The New Childrens Encyclopedia
What is science? Science is the search for knowledge about the world and the way it works. Unlike other ways of explaining how t ...
Biology is the scientific study of living things. Its many branches are devoted to different kinds of life, including botany (th ...
Mighty atoms Everything is made up of atoms. These incredibly small particles are the building blocks of all matter, from the ro ...
SCIENCE OAlso known as biotin or vitamin H OFirst isolated in 1941 by Vincent Du Vigneaud Vitamin B 7 is one of eight molecu ...
224 SOLID STATE The atoms or molecules in a solid substance are held together by electrical forces. They are arranged in a repea ...
SOLID, LIQUID, OR GAS? 225 SCIENCE LIQUID STATE The atoms or molecules in a liquid substance can slide over each other, so a liq ...
226 Mixing chemicals A few common substances are made of just one chemical, such as pure water or pure salt. Most of the things ...
MIXING CHEMICALS 227 SEPARATING MIXTURES AND COMPOUNDS CHEMICAL REACTIONS When the atoms of two or more substances rearrange the ...
228 It’s elementary An element is a pure substance that cannot be broken down into simpler chemicals. An element is made of only ...
IT’S ELEMENTARY 229 SCIENCE ■ Group Transition metals ■ Discovery date Unknown (prehistoric times) ■ Melting point 2,800ºF (1,53 ...
Energy Energy is the power behind our world. Although you can’t see it, you can’t do much without it. Whenever things move, ligh ...
SCIENCE ■ Percentage of current energy use Less than 1 percent ■ Reserves left Unlimited Almost all the energy on Earth original ...
232 SCIENCE Feel the force Forces are at work all the time, pulling you down to the ground, stopping you from slipping over, and ...
FEEL THE FORCE 233 MAGNIFYING FORCES People use machines to magnify forces. Machines called levers move around a fixed point cal ...
Gravity is the force of attraction that pulls things together. On Earth, we experience it as the force that pulls us down onto t ...
GRAVITY 235 SCIENCE GENIUS Sir Isaac Newton was the first person to figure out that the force of gravity keeps the Moon trappe ...
236 Electricity Everything in the universe is made up of atoms that we can’t see. Each atom has particles that transport an elec ...
ELECTRICITY AND MAGNETISM 237 Magnetism Whenever there is electricity, there is magnetism. This mysterious, invisible force draw ...
Science of sound Sound is a form of energy. It passes through air, water, and solid objects as invisible waves. We can hear soun ...
SCIENCE OF SOUND 239 100 dB The blast of a car horn. 110 dB The sound of a thunderstorm overhead. 120 dB The roar of a jet ...
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