TESTING THE STRENGTH OF DIFFERENT COLORED EGGSHELLS. Savannah Lu. Cary Academy ABSTRACT

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1 TESTING THE STRENGTH OF DIFFERENT COLORED EGGSHELLS Savannah Lu Cary Academy ABSTRACT The purpose of this experiment was to test which eggshells were stronger, white or brown. The hypothesis was when the two eggs were bumped against each other; the brown egg would not be the first to crack. The main experiment was done in this way. A pair of eggs, one brown and one white, was bumped against each other and the egg that did not break first was determined to be the stronger one. The hypothesis was proven to be true and the brown egg was stronger than the white. Out of the six trials, the brown egg only broke once while the white egg was the first to break five times. The second experiment concluded a little differently. Instead of damaging the eggs with other eggs, they were hit by weights dropping down from different heights. From a drop of 6 cm, it took three hits to break the white egg while it only took two hits to break the brown egg. However, on a drop of 9 cm, the brown egg required two hits to break while the white only took one hit to break. Overall this experiment showed that the brown eggs were stronger than the white eggs. INTRODUCTION The purpose of this experiment was to test if the brown eggs have stronger shells compared to the white eggs. Both the brown eggs and the white eggs that were used were bought from Harris Teeter and were grade A large. They had the same oval shape. However, there are some differences observed between the two types of eggs. It was found that the white eggs had more mass than the brown eggs. The white eggs on average had a weight of 57.5 grams, while the brown eggs weighed on average 57.2 grams. In addition, the brown eggs were found to have brown and black spots on the eggshells, but the white eggs did not. Could that affect the strength of an egg shell? The

2 answer is yes. According to ebsco.com, the spots on an eggshell make it stronger so it can stand the weight of the mother. Why are some eggs brown while others were white? It all depends on the chicken that laid it. White-feathered chickens with white ear lobes lay white eggs and red-feathered ones with red ear lobes lay brown eggs, but there is no difference other than the color of the eggs. Brown eggs are more expensive though. According to farmers who produce brown eggs, the chickens which produce brown eggs eat more. There are many types of eggs such as amphibian eggs and amniotic eggs. The amniotic egg is one type of eggs that holds fluid to protect the embryo. Reptiles, birds and mammals produce this kind of eggs. Unlike amphibian eggs, amniotic eggs have a hard outer shell. The shell is just one important part of the amniotic egg. Other parts include the yolk which gives a rich food supply, the allantois which stores the embryo or the baby's wastes. The albumen provides water and protein for the embryo. The amniotic sac is filled with liquid that surrounds and protects the embryo. Picture of Amniotic egg (Figure source:

3 Ninety five percent of an eggshell is made up of calcium carbonate which is also the same material in chalk and limestone. The remaining 5% is made up of calcium phosphate, magnesium carbonate and some proteins. It was hypothesized that the brown eggshells will hold up better than the white eggshells when the two colored eggs are bumped together. MATERIALS AND METHOD Brown grade A large eggs White grade A large eggs Pot In this experiment, the control was the white eggs due to the fact that the white eggs were less expensive than the brown eggs. The independent variable was the different types of eggs or the different colors of eggs since that was what changed the dependent variable. The dependent variable was how many times one color of eggs had cracked first. Things that remained the same between the two different types of eggs were that each type were boiled at the same time for ten minutes and then put in the refrigerator. Also both were bought from the same store with the same brand. First the eggs were boiled for ten minutes all at once. Then the eggs were placed in the refrigerator to cool off. Next the eggs were taken out and held over a large pot so the eggshells that might fall off when cracked would not go all over the place. After that, the eggs were gently bumped together against each other. The egg that did not crack first was determined to be the stronger one. This was repeated 6 times. In the second experiment, the control was also the white eggs. The independent variables were the different types of eggs and the height of the 200 grams weight dropped in centimeters. The dependent variable was the number of hits that took to break the egg. Three controlled variables in this experiment were that the same cup

4 cushioned with the same brand of paper towels, the eggs were all boiled, and the same weight was used. First the egg was cushioned with paper towels inside the cup until the egg was tight inside the cup. Then, the ruler was lowered inside the cup against the egg. When the ruler was aligned with the egg, the weight was placed at the desired height and then dropped. This was done with the heights 6cm, 7cm, 8cm, and 9cm. In the third experiment, the control was the silly putty inside the Easter egg due to the reason that the silly putty represented the yolk inside the egg. The independent variable was whether the silly putty was in the Easter egg or not and the height of the 200 gram weight dropped at. The dependent variable was the amount that the silly putty was affected by the weight. Three controlled variables were that the same color of Easter egg, the same cup with paper towels and the silly putty made into the same shape every time. First, the silly putty was cushioned with the paper towels in the cup. The ruler was aligned against the silly putty and then the weight was placed against the desired height and then dropped. In between each test, the silly putty was shaped back into the shape of an egg after being damaged by the weight. The same was done for the silly putty in the Easter egg. Heights where the weight was dropped from were 6 cm, 7 cm, 8 cm, and 9 cm. RESULTS AND DISCUSSION

5 How many times the egg cracked first Brown Type of egg White Figure 1: Results of Experiment1 In the first experiment, six pairs of eggs, white eggs vs. brown eggs, were bumped against each other to see which egg was broken first. The result of the first experiment was presented in Figure 1. Out of six trials, the brown egg cracked first was 1 time while the white egg cracked first 5 times. When conducting this experiment, the brown egg s top part was found to be stronger than the rest of the egg (top= smaller end of egg) while the white egg s bottom seemed to be stronger. This experiment proves that overall the brown eggshell is stronger than the white eggshell. When conducting the experiment, sometimes the top part of an egg hit the bottom part of another egg, and other times the side part of an egg hit the bottom or top part of another egg. As observed, different parts of the eggshell may have different strengths. Thus the experiment was not done under good control on this part.

6 Number of hits it takes to break egg Height of weight being dropped(cm) Figure 2: Results for brown eggs in Experiment 2 In the second experiment, weights were dropped on the eggs from different heights to see how many hits it would take to break the egg. The results for the brown eggs and white eggs are shown in Figure 2 and Figure 3, respectively. In this experiment, there were four trials for each types of eggs. It took two hits to break the brown egg when the weight was dropped from the height of 6cm. For the heights at 7cm and 8cm, the egg was broken with one hit. However, it took two hits when the height was 9cm. This was unexpected. The results of the white egg were similar to that of the brown egg, except that it took 3 hits at the height of 6cm. Also at the height of 9cm, the white egg was broken by one hit. This was a relationship experiment. It was expected that for both types of eggs, the relationship between the number of hits and the height would be inverse. The experiment results from the white eggs confirmed the expected relationship. The brown egg however, had one unexpected result at the height of 9cm which caused the relationship to turn in a different direction. The maximum number of hits it took to break the brown egg was 2 while the maximum number of hits that took to break the white egg was 3. This makes the white eggs

7 Number of hits it takes to break egg appear to be stronger than the brown eggs, which is the opposite results that were found in experiment 1. This information might not be accurate though, things would have happened differently if more trials were done. For the last trial, the weight that was dropped could have been slanted or dropped on the side of the egg Height of weight being dropped(cm) Figure 3: Results for White eggs Experiment2 Height of weight dropped(cm) Result of impact 6 Made a few scratch marks 7 Barely shifted shape 8 Barely shifted shape 9 small spot squashed flat

8 Figure 4: Results for Just Silly Putty in Experiment 3 For the third experiment, Figure 4 shows the results of just silly putty being hit by the weight. Figure 5 shows the results for the silly putty inside the Easter egg being impacted by the force of the weight dropped down on it. It was found that the silly putty by itself was less affected by the weight than the silly putty inside the plastic egg. The silly putty by itself was most impacted by the weight was when it barely shifted shape at the drops of 7 cm and 8 cm. The silly putty inside the egg was damaged the most when it changed shape a lot at the drop of 7 cm. Height of weight dropped(cm) Result of impact 6 squashed flat 7 changed shape a lot 8 nothing changed 9 nothing changed Figure 5: Results for Silly Putty in Easter egg Experiment 3 CONCLUSIONS The hypothesis was right. The brown eggs were stronger. Out of six times, the brown eggs only cracked first once. Based on the research, the inferred reason why the brown eggs were stronger was that the chicken laying brown eggs on average are heavier than the chicken laying white eggs. Strong eggshells of brown eggs provide good protection from the heavy mother chicken. Things that could be improved would be making sure that the whole egg is being tested on its strength and not just one part of the egg. In the future, another experiment that could test the strength of an egg is by doing an egg drop with the egg wrapped with cushions. The second and third experiments were extension of the first experiment. In a second experiment that was conducted, it was found that when dropping the weight from 6cm, it

9 took 3 hits to break the white egg while it took only 2 hits to break the brown egg. The results are somewhat unexpected. Future experiments with more trials are needed. REFERENCES Conrad Jack "The structure of an amniotic egg." Introduction to the Amniota.Ucmp web. Feb,2013 Diffin. "Differences and similarities."brown eggs vs. white eggs. Diffin. Web. Feb 2014 Gosler, Andrew."Low calcium eggs show their spots." New Scientist. Ebsco Vol. 187 Issue 2517 p13-13.print National science teachers association."the amazing amniotic egg." Animals..Austin, Texas.A harcourt education company Print Senese, Fred. "What Are Egg Shells Made Of?" General Chemistry Online: FAQ: Chemistry of Everyday Life:. Frostburg State University Web. 19 Feb Spangler, Steve. Fire Bubbles and Exploding Toothpaste: More Unforgettable Experiments That Make Science Fun. Austin, TX: Greenleaf Book Group, Print. Spangler, Steve. Naked Eggs and Flying Potatoes: Unforgettable Experiments That Make Science Fun. Austin, TX: Greenleaf Book Group, Print