1. Chemical Lighting Experiment By Isabella Hinojosa 12/7/09 Biology P.3 Science Fair

2. Big Question My big question is what does chemical lighting do to human hair? My question is to find out if the chemicals effect the hair’s structure.

3. Hypothesis If human hair is dyed then it will affect the hair’s structure. I thought this because I think the chemicals of the lighting dye will affect the hair cells by making them weaker.

4. Interesting Facts When I was rinsing the dye from the hair, the hair was really rough. When the hair was dry, it still felt rough and it was also thinner. When I put the hairs on the hygrometer, the hair that was not dyed, made the pointer go up and the others that were dyed went down. The dyed hairs had more pores than the natural hair. It took awhile for the dyed hairs to react to the humidity.

5. Experiment Materials: 3 strands of human hair Hair dye lighter than the human hair Tint brush Plastic or glass bowl Protective gloves Goggles Aluminum foil Sheet rock Flat piece of plastic 6 small nails 3 dimes Tape Hammer Scissors Rubbing alcohol Water Cotton swab

6. Experiment/Procedure 1. Make one hygrometer from each of the hairs. 2. To make a hygrometer you need to cut a triangular shape of plastic. 3. Tape a dime on the pointer. 4. Poke a hole with the nail near the base. Wiggle it so it can be loose. 5. Put the pointer on the sheet rock and attach the nail. Make sure that the pointer spins easily. 6. Put another nail one inch from the top of a base in line with the pointer. 7. To chemically lighten a swatch of hair, secure one end of the hair with an elastic band. 8. Keep one hair untreated 9. Mix hair dye in a bowl. 10. Put the hair on a piece of aluminum foil. 11. Put the hair dye mixture on the hair with a brush.

7. Experiment/Procedure 2 1. Time how long you leave the piece of hair with the dyeing solution. 2. Rinse the hair with water. 3. Dry the hair. 4. Label each hair. 5. Make a solution of 20% of alcohol and 80% of water. 6. Use a dab of this and put it on the cotton swab and wipe it on the hair. 7. Tape the hair between the dime and the nail hole. 8. Carefully pull the hair taut, so the pointer’s point is parallel to the floor. The point should be perpendicular to the hair. The hair should be perfectly vertical and the pointer should be perfectly horizontal. 9. Tape the free ends of the hair to the top nail. If the hair is too long, cut the ends. 10. Test the hygrometers in humidity. Put them in the bathroom. 11. Close the door and turn on the shower for five minutes. 12. Analyze and write down what happens in ten minutes.

8. Controls/variables I didn’t have any controls or variables.

9. Observations from Experiment I saw that the hairs that were dyed were bad in the humidity because they had too many pores. I also saw that the dye made the hairs thinner and rough. I saw that the hygrometers have to be in place because if it not it won’t do any thing. I saw that the hygrometers have to be pretty high from the ground because the humidity won’t get down there.

10. Data My 1 st swatch of hair was untreated and it was a really dark brown and it was very thick. My 2 nd swatch was lightened for 25 minutes. When it was done it was reddish brown and still thick, but not as thick as the first one. My 3 rd swatch was lightened for 45 minutes it was a light brown and it was thin. In the humidity, the 1 st hygrometer with the 1 st swatch, made the pointer go up. The 2 nd hygrometer with the 2 nd swatch, made the pointer go down. The 3 rd hygrometer with the 3 rd swatch, made the pointer go more down than the 2 nd one.

11. Analysis of Data By doing this experiment, I was able to test my hypothesis, that the structure of the hair will be affected by the chemicals of the hair dye. Doing the analysis of the data, I was able to see that the dye made the hair lighter and thinner. Also the test for humidity showed that the hairs that were dyed, accept more water and makes them heavier.

12. Conclusion My hypothesis is correct. When human hair is dyed it affects the structure of the hair. I would change this experiment by adding another step, dying a piece of hair darker than the natural hair because I did this experiment with my own hair and I want to see what would happen if it is dyed in a darker color. Some of the new questions I have are: Will it be stronger? Will the hair be thicker? My hair is very dark, will it get darker? Doing this experiment made me learn many things of human hair and hair dyes.

13. References http://www.sciencebuddies.org/