Air and Water?

Air and water are two materials with which everyone is familiar. We live at the bottom of an ocean of air, called the atmosphere. Air surrounds our bodies every minute of our lives, expect when where swimming and bathing. Air may be found almost open hallow in all materials on the surface of the earth. There is air also in many of the hallows and opening of the human body-for example,  our ears, mouth, nose and lungs. All animals breath air, and if deprived of it, they die.

     The waters of seas, lakes, rivers, and streams, cover three-quarters of the earth's surface. Water is necessary for life. The cells of which living things are made are largely water. Water, given enough time, will dissolve almost any substance. this is important, because the materials that nourish living things are dissolved in water. This water makes up the main part of the blood of animals and the sap of plants, the two fluids that carry nourishing materials to cells of living things.

     We shall perform experiments concerning both air and water, because, as we shall see, these two materials are closely connected in many ways.

How Can You Change the Color of a Leaf?

You will use:

     Drinking glass
     Celery stalk
     Red Ink
     Water

Do this:

1. Add red ink to the half-glass of water.

2.Place a celery stalk in the glass. Leave in there for several hours.

3.Cut the stem should red.

4.Cut the stem crosswise in several places to see the tubes that carried the water to the leaves.

Why it works:

     A the colored water was the inside of the tiny tubes in the celery, they draw the water up higher that the level of water in the glass. this is called "capillary action".

Everybody Talks About The Weather

Important Words:

     Barometer - An instrument used to measure the pressure of the atmosphere.
     Thermometer - An instrument used to measure temperature.
     Meteorology - Science dealing with the study of atmosphere and weather.
     Humidity -  Amount of water vapor in the air.
     Radiosonde - A radio device carried aloft by balloon, which relays atmosphere pressure, temperature,    and humidity.

     The weather affects all of us in one way or another, directly or indirectly. A dry spell or a freeze may lessen the yield or fruit, and perhaps destroy some crops entirely, thereby causing shortage of food in some areas; and a short supply means either paying higher prices or doing without. A change of weather can bring about a change in plans, ranging from a battle to a picnic or parade.

      The first thing may people do is in the morning is to look out the window " to see what the weather is." If they have an outside thermometer, they look at that to see what the temperature may be. Or they may consult a barometer. Or they may turn on the radio to get weather forecast. Then based on this information, they will decide what kind of clothes to wear.

     Knowing what the weather will be is important to the farmer, the fisherman, the captain of ship, the pilot of airplane, and people in other occupations. Specially trained people provide this information. These weather people are called meteorologists.  They study the winds, clouds,storms, and other natural happening in the atmosphere.  From what they find out, they try to predict the weather for airlines, electric companies, transportation companies, radio and TV stations, and the Weather Bureau. They assemble weather reports from all over the world, study radar pictures and data received form weather satellite, and carefully determine what kind of weather is moving toward us.

Safety Rules

1. Never touch a switch with wet or damp hands.

2. Never poke around inside a radio or television set if it is switched on.

3. Never pull the chain of light bulb if you are standing on a wet floor.

4. Never touch a broken utility pole wire during or after a storm, or even when the sun is shining. Call a police man or a fireman.

5. Never touch an electrical appliances, switch,radio, or television set while in the bathtub or shower.

6. Never put electrical wires under carpets.

7. Never put anything but an electrical plug into a wall socket. Don't connect more than two appliances to a plug.

8. Never Remain in a lake during a thunderstorm.

9. Never remain under or near a tree during lightning-thunder storm. Get away from the tree lie flat on the ground.

How Can You Make a Horseshoe Electromagnet?

You will use:

     Long, thin bolt (or U-Bolt)
     Insulated copper wire
     Dry Cell
     Switch
     Small nails paper clips

Do this: 

1.Wind several layers of wire around one arm, then other, of a  U-Blot. (Such a blot, if unobtainable, may be made by bending a long thin bolt into a U-Shape, using a vise)

2.Strip the insulation form the ends of wire.

3.Connect one end of a  piece of wire to one terminal of the dry cell, and the other end to the terminal of the switch.

4.Connect a second piece of wire between the dry cell and the switch.

5.Close the switch. How many paper clips or nails can you pick up your horseshoe lectromagnet?

6.Open the switch. What happens? Try this several times.

Why it works:

     We already know why an electromagnet works.

     We are now able to take advantage of an electromagnet shaped like horseshoe?

     We are now able to take advantage of magnetism produced in both ends,  or poles, of both electromagnet. When both poles are near each other, we get up twice the strength that a straight bolt gives- if the number of turns of wire is the same on each side.

How to Make an Electromagnet?

You will use:
     Lantern dry cell
     Wire
     Switch
     Large Nail
     Small nails or paper clips

Do this:

1.Wind about ten turns of wire around large nails.

2.Strip the insulation form the end of the wire.

3.Connect one end of the wire to one terminal of a dry cell, and  the other end to a terminal of the switch.

4.Prepare second wire. Connect this wire to the other terminal of the dry cell and the other end of the switch.

5.Now close the switch, and try to pick up paper clips. Open the switch, and the small nails or paper clips fall.

Why it works:

     Electricity from one part of the dry cell flows through the many turns of wire back into the dry cell.

     When electricity flows through a wire,  the wire has magnetic power around it. If the wire happens to bein the form of coil, the magnetism is even stronger.

     An iron nail inside the coil become a magnet. This is true only so long as the electricity is flowing in the circuit. It is a magnet when you want it to be.

How to Make a Switch?

You will use:

     Electric lantern cell
     The bulb with wire attached that you just made
     Bell wire
     Strip of metal
     Block of Wood
     Nails
     Hammer

Do this:
1.Take a piece of metal 4 inches long and 1 inch wide. You can cut it form a tin can if you are careful not to cut yourself. Use the kind of scissors called  tin snips. Wear gloves.

2.Nail one end of the metal strip of the block wood. under the end of the metal.

3.Do not hammer either nail all the way down in the wood.

4.Bend the free end of the metal strip upward so that it is not resign on the nail beneath it.

5.Now you have a switch.

6.Connect one end of a length of wire to either terminal of a dry cell. Connect the other end of the wire to nail under free of the metal strip.

7.To connect a wire to the lantern cell, just twist the bare end of the wire around of the strips on the top of the cell.

8.Be sure to scape the insulation off ends of all the wires you see.

9.Using the lantern-bulb-and-wire-device you just  made, connect one end of wire attached to the bulb to the other terminal of the dry cell.

10.Connect the other end to the nail holding the strip of metal in place.

11. Now place the switch

12.If you have made all the connections right, the circuit is loaded, and the bulb will light.
13.Don't hold the switch down for more that few seconds. The dry cell will wear out.

14.Save this switch. You will probably use it many times.

15.A switch is a convenient way to open and close a circuit. It is easier that connecting and disconnecting wires.

16.Use your switch only with a dry cell. Don't try to use switch with any household electrical appliances or lights. YOU MAY BE KILLED.

Electricity-Magic at Your Finger Tips

Important Words:

     Dry Cell - A metal container filled with a paste made up of chemicals that procedure electricity.
     Electron - Tiny particle that carries a minus particle of electricity.
     Circuit - The round-trip path from a source of electric current, through wires, and back to the source.
     Volt - Unit for measuring the push of an electric current.
     Watt - Unit for measuring electrical power.

     We have been told that magic has no place in science. But if Benjamin Franklin could see some of the modern uses of electricity, he might say, "It uses be magic!".

     Just think how you use electricity today. Were you been awakened by an electric alarm clock? Did your father shave with an electric razor? Did your mother make wraffles on electric waffle iron?

     Did you watch telivision before going to school? Did you ever stop to wonder what makes your door chimes and telephone work?

     Were the lights on in your classroom? Did your principal speak to school over the loudspeaker? Did you see a movie or a filmstrip in class?

     Think of all the other things in the world electricity makes work, and will see why anyone might use the word "magic" for it.

     A magic trick, however , cannot usually repeated successfully at home but many specific experiments can be carried out by anyone. In fact, it isn't always necessary to have a great deal of equipment. Much of it can be homemade.

     So let's forget the word "magic" and replace it with "understanding" and "knowledge".

     When a scientist is puzzled by something, he tries to find the answers by doing several things. He observes whatever puzzles him very carefully. He then writes down what he sees. Then he studies the information to see of he can see the idea about it. He calls the idea a theory. Next he experiment to prove whether or not the theory is correct.

     Scientist have theory about what electricity is. to understand this theory, we must begin with another theory.

     Every object can think of is made up of molecules, the smallest particle into which anything can be divided and still keep its original qualities. If we break up a molecule, we have atoms, which are much smaller particles. For instance, water (liquid) is made up of two atoms of hydrogen and one of oxygen (both gases until they combine from water). If we break down the water molecule, the hydrogen and oxygen to their original state as gases.

     All things in thw world are made up of combinations about 100 atoms. That is why they called atoms "buildning blocks" of the universe.

     Atoms, themselves, are composed of still smaller particles called electrons, protons,neutrons, and several others.

     Scientist tell us that electricity is made up of electrons, each of them carying a small electric charge. When we get this electrons to move, we have an electric current-electricity.

    We make these electrons move by using big machines called generators, which produce electricity. Energy to some generators comes from burning coal or oil. In some places near rivers, some of the river water is made to fall through a slots in a dam. The falling water strikes larges wheels that have spokes made of metal blades attached to a central rod, or axle. The axle spins fast, making the generator run and produce electricity.

Can You See a Rainbow Other Than in the Sky?

You will use:
   A triangular piece of glass from a chandelier. A piece of glass of this shape is called prism.

Do this:
   Hold the prism in sunlight. If you don't see rainbow colors, move the prism until you see rainbow's beautiful colors.

Why does it work?
    White light, such as sunlight, is made up of seven colors: red,orange,yellow,green,blue, indigo and violet. When white light is refracted by the prism, the light break up into these seven colors and we see a "rainbow"

     A real rainbow is caused by sunlight being refracted through small raindrops high in the air.

How Can You Bounce Light?

You will use:

   A small mirror

   A flashlight

Do this:

     Place the mirror on the floor. Shine a flashlight on it. A patch of light will appear on the ceiling or nearby wall. Move the mirror quickly. Move it slowly. Direct it to other parts of the room.

Why Does it work?

    Some rays of light landed on the mirror and bounced right off- that is, the light rays were reflected to wall. 

     If you notice carefully, you will see that the rays reflect off the mirror at exactly the same slant, or angle, that they hit it. This shows us to that light travels in straight lines.

    

     People in hot climates wear white clothing. Why? We learned that white is light-colored materials reflect light well, and black or dark-colored materials absorb it well.

Rays reflect off mirror at the same angle they hit it.

     So in the summer it is wise to wear white light-colored clothing that will reflect the sun's hot rays away from you. Dark-colored or dark clothing will absorb the sun's hot rays and make you feel very hot.

What is light and What Does It Do?

     What would the world be without light?  Go into a dark room and cover your eyes with your hands. open your eyes wide. What do you see? Nothing. What you just did shows that without light entering your  eyes you could not see anything.

     Now go into a room that is brightly lighted. What re the brightens things in this room? The electric light bulbs in lamps or in light fixtures. Or fluorescent light tubes. These things are making the light that is in the room. Things that make light are called light sources.

     Go out of the houses. Do you see any light sources? If it is day, you see a big one-the sun. If it is night, you see light coming from the streetlights and,  maybe, from advertising signs. If the sky is clear, you see thousands of stars. All of these things are light sources- they make their own light. The sun is white-hot and sends out a tremendous amount of light. The stars are suns very far away from the earth. If the streetlights you saw had electric light bulbs,  the light source inside them was a thin wire made a glow white-hot by sending electric current through it. Or streetlights may have had florescent lamps, which are filled with a kind of gas that causes the lamp to glow when electric current is sent through it.

     What about the moon-  is it a light source? And a planet Venus, which shines like a bright stars? The moon, Venus, and other planets shine because form the sun strikes them and then bounces to the  earth- to your eyes.

     Go back into the house. Look  at all the things you can see that are not light sources. You see them because light the sources strikes them and bounces off them your eyes- the way a rubber ball bounces off a wall. Bounced light is called reflected light.

     Things with smooth surfaces reflect more light that others. The light that is more reflected is absorbed. An object that reflects no light- that absorbs it all- looks black. Between those things that reflect all light and those absorb all light are things we see in different shades. The light shade of blue that is like a robin's egg reflects more light than the dark shade of blue that is like a sailor's navy blue uniform. The navy absorbs more light

     Light travels in straight lines. That is why can't see around a corner.

     Throughout history many scientist have had ideas or theories about what light is. In the early part of the 20th century a scientist named Max Planck put forth a theory that light is made up of extremely tiny bundles of energy called photons. Bundles of photons are called light rays. The rays travel away from a light source in the same way rings of the water move away from the place where a stone strikes the surface of water. Light rays travel in straight lines. This is a very important about light.

Light in Our Lives

The caveman's torch made a little in the darkness. Today we light whole cities with electricity.

Important Words:

   Photon - A tiny bundle of light energy.
   Reflection - Bouncing of light rays in the straight lines.
   Refraction - Bending of light rays as they go from one substance to another.

     Have you ever heard someone say, "Turn the light on- I can't see a thing"? For most o the time thats human begins have existed, the only light that they knew was sunlight, moonlight, and starlight, or, somethimes lightning.

      They had to hunt and fish during the day. Later, when they ploughed fields and raised crops, they could work only from dawn to dark. Then they learned to use fire. It lighted their caves and, later houses. Light from fire places was only the light some houses had. Abraham Lincoln read and studied by the light form his fireplace. After learning to use fire, people learned to make oil lamps and then candles. they learned to burn gas to light their homes and streets.

     About 100 years ago, Thomas Edison invented electric light, and  humans had conquered the darkness of night. We would work and study and travel and play whether it was day or night.

Reference: Beginning Science By: Dr. Jerome J. Notkin