Red Light White Bar Crystal example essay topic

Table of contents Introduction... 3 Review of Literature... 3 Purpose o f Study... 7 Hypothesis...

7 Variables... 8 Procedure... 8 Methods and Materials... 9 Results... 9 Graph "A."..

10 Graph "B.".. 11 Conclusion... 12 Unexpected Findings... , ... 12 For Future Study... 13 Bibliography...

13 Acknowledgments and Credits... 13 Appendix... 14 People have been fascinated with crystals since before civilization. Crystals can be found in stream beds and in rock outcroppings. Sometimes people would even mine crystals in caves. We have been attracted to crystals because of their extraordinary beauty.

Some crystals are valued for their rarity and color, and are known as gems. People believed that crystals were magic and could be used for medicinal qualities. They were used as valued items of barter. People still value crystals for different uses. It varies from jewelry to electronic components in advanced electronic instruments. We see crystals all around us in our daily lives.

Many construction materials such as brick, stone and concrete contain a large amount of crystalline materials. Common medicines such as alka-seltzer are crystalline. Also common foods are crystals such as sugar, salt and baking soda. Most of the time chemicals can be transformed into crystalline forms.

The focus of this study will be to grow crystals from a crystal growing kit under different colored lights. My examination will concentrate on the growth pattern of crystals when placed under a red light, a white light and in total darkness in determining the differences, if any, in the crystal growth. The Study of Crystals The study of crystals: their form, growth, structure, chemistry, bonding and physical properties is called crystallography. Crystals with symmetrical external forms were among the first to be studied. The Danish scientist Nicolaus Steno, published his observation on crystal growth in 1669. These concluded what is now Steno's law, on the constancy of a crystal's interfacial angles.

He noted that the faces, or flat surfaces of crystals of the same compound always intersect at the same angle, whatever the size of the crystal or the relative sizes of the faces. Steno's law states that the building blocks of crystals, which is now known as the atom, are very small and that they are added according to a consistent pattern. Modern crystallography uses x-ray diffraction to determine and better understand crystal structures. Scientist also continue to find new methods of crystal study.

In the 1960's, transmission electron microscopes were developed that made possible the study of electron diffraction by crystals. Furthermore, Transmission Electron Microscope images of very thin crystals provided visual evidence of some "mistakes" in crystals patterns such as, missing atoms and layer offsets. Scanning tunneling microscopy (STM) was developed in the 1980's. It uses a very fine-tipped tungsten stylus to map the atomic topography of crystal surfaces.

Because crystals interact with their surroundings across their surfaces, STM studies are providing important information about crystal growth and dissolution as well as adsorption of substances onto crystal surfaces. Crystals A crystal is a solid in which the atoms are arranged in a three-dimensional pattern. A pattern, called the crystal structure, can be described in terms of geometrical arrangement of a small number of atoms, called the unit cell. This unit cell is repeated again and again in a regular way to create the crystal.

Some crystals have simple patterns (structures) and only one or a few kinds of atoms -- for example, copper metal (Cu) and table salt (NaCl). Others have complicated structures, such as proteins, or many kinds of atoms, such as tourmaline. The unique physical properties of a crystal reflect its structure, its chemical composition, and the nature of the bonding among its atoms. Crystals are much more common than most people realize.

You can find crystals all around you in your daily life. Computers, Televisions and radios all utilize the crystals of solid state physics. A lot of building materials such as stone, brick and concrete contain a large amount of crystalline materials. Ice cubes and snowflakes are also crystalline.

Common medicines such as alka-seltzer and aspirin, and common food such as salt, sugar and baking soda are all crystalline. It is the orderly arrangement of atoms that makes a solid a crystal, not its external form. Only in special cases -- such as snowflakes -- have crystals grown so much that their shape gives clues to the internal pattern. For example, ice cubes are made of ice crystals with the same crystal structure as snowflakes. The crystals in ice cubes, however, generally do not have the six-sided form of snowflakes because their growth was inhibited by other crystals in the ice cube tray. Every metal object is made of one or more types of tiny crystals, commonly too small to see without a microscope.

Almost every kind of pottery and ceramic tile is made of crystals, although the glaze may be amorphous, that is, glassy, with no order or pattern to the arrangement of atoms. Almost every rock is made entirely of crystals known as minerals. In fact stating that almost every rock is crystalline most of the earth is too. Sand and clay are collections of small and microscopic crystals. Even teeth are made of crystals.

Gypsum crystals make walls smooth, quartz crystals help people to keep time, hematite crystals set in plastic tape make possible the recording of movies for video cassette players, luminescent crystals enable television screens to glow, and silicon crystals grown in layers to make computers possible. Crystal Fascination Since the beginning of civilization people have been fascinated with crystals. People have been attracted by their extraordinary beauty. Some crystals, called gems are valued for their rarity and color. Some people also believe that crystals have magical powers such as love, hope and energy. They are also believed to have certain medicinal qualities such as healing.

Light Light is electromagnetic radiation in the wavelength range extending from about 0.4 micron to about 0.7 micron. Or, perhaps more adequately, the visual response to electromagnetic radiation in this range. The term is frequently applied to adjacent wavelength ranges that the eye cannot detect: ultraviolet light, infrared light, and black light. In addition to wavelength, frequency, in hertz, and wave number, in inverse units of length, are also used to specify and designate the character and quality of the radiation. Associated with wavelength or frequency is the visual response of color. The term monochromatic is applied to the idealized situation in which the light in a beam is all of one wavelength.

Light Production Light, like any other electromagnetic radiation, results from either an accelerating electric charge or a nuclear fusion or fission reaction. In nuclear reactions, a photon is created in the same manner as other elemental partial products of the reaction. With the exception of sunlight and starlight, nevertheless, light usually is the result of changes in the electronic structure of atoms and molecules as they absorb and readmit energy. Purpose of the Study The purpose of the study was to determine if there is a significant difference between the growth of crystals grown with red lights, regular white lights and crystals grown with no light at all. Hypothesis The red colored light will have a different effect on crystal growth... I think that crystals will be bigger than the ones grown under white light and no light, when grown under a red light and that crystals grown under a white light will be bigger than no light at all.

This belief is supported due tho the facts that red light produces more heat than white light and white light produces more heat than no light at all... The crystal method I used was the evaporation method, and evaporation takes place faster the more heat you have. So red lights supply more heat and the solution should evaporate faster causing the crystals to grow bigger. Variables My independent variable would be the color of the lights. My control variable would be the white light. My dependent variable would be Procedure In order to carry out this experimentation two light bulbs, red and white, must be purchased.

The GE brand was purchased because of the availability and they were the only brand which had red and white light bulbs in 25 watts. At the start of my research I had to make a crystal solution by dissolving and boiling 100 mili litters of water and 230 grams of sugar for each jar until the solution became clear. After the solution is made for all three jars one was placed under a red light bulb another was placed under a regular white light bulb and one was placed in total darkness. The lamps with the light in them were 8 inches away from the floor. They stayed there for 2 or 3 days and sugar crystals began to form at the bottom of the jar, if the crystals do not appear at the bottom of the jar throw in little grains of sugar in.

The jars we left there uncovered for about a week. Look for a nicely sized crystal called the "seed crystal". Dry the seed crystal and tie an invisible slip knot around it with an invisible thin fishing line. The other end of the string was tied around a block of wood and the crystal is washed in cold water before being placed in the solution. Let the crystal hang in the water 2-3 cm (about 1 inch) from the bottom of the jar... Do the same to all three jars.

Leave them uncovered so water can evaporate. When the water evaporates the crystals grow. Crystals should grow onto the seed crystal and string and on the bottom of the jar. Materials -3 Barilla jars (cleaned) -GE brand white light bulb 25 watts -GE brand red light bulb 25 watts -230 grams of sugar per jar -100 grams of water per jar Results Graph "A" shows the size of the crystals before they were placed under the lighting. They were all the same size before the experimentation began. Graph "B" compares the size of the crystals after the experiment was finished.

Graph"A" and Graph "B": Red bar = Crystal grown under red light White bar = Crystal grown under white light Black bar = Crystal grown under black light NOTE: Measurements are in inches NOTE: Measurements are in inches Conclusion The purpose of the study was to investigate the growth of crystals under different lighting. It was hypothesized that crystal would be bigger when grown in red light than white light and that white light grown crystals would be bigger than crystals grown in no light at all. This belief was supported due to the fact that lights produce heat and colored lights produce more heat than white light. Since the crystals were grown from an evaporation method and heat makes evaporation faster, the red light should make the solution evaporate faster causing the crystals to grow bigger. The crystals were grown from a sugar and water solution. Three jars of crystals were made and each jar was placed under different lighting.

One jar was placed under a red light, one under a white light, and when was grown in the dark. The results showed that the crystal grown in the red light was the biggest, the white light was the second biggest, and the crystals which were grown in the dark were the smallest. Therefore my hypothesis accepted. Unexpected Findings Unexpected findings from this study included the problems I had while running this experiment. The first time I tried growing the crystals, the instructions were unclear and I had to start over. The second time I tried one of my friends thought it was candy and tried it.

I finally succeeded on my third try. For Future Study I think there should be more studies on the growth of crystals under different lighting. I found no testing done in this area while I was researching. Perhaps different types of crystals and different colored lights can be used during testing. Acknowledgments and Credits Credits: Mr. Thomas helped me a lot with my science fair project. I ran into a lot of problems during my experimentation and he helped me solve them.

My mom bought me all the supplies I needed and went out of her way to help me find the crystals.

Bibliography

A. Smithsonian Crystal Growing Set Pamphlet kit series 1 B. crystals The 1996 Groiler Encyclopedia CD-ROM C.
lights The 1996 Groiler Encyclopedia CD-ROM.