A few weeks ago, when our class was learning about physical and chemical changes, I had my students complete a week long experiment to review the scientific process and observe a chemical reaction.
Needless to say, that as soon as I mentioned that our experiment for the week was called The Naked Egg Experiment, students began to giggle. Of course, I acted like I did not understand what they were laughing at by questioning "What's so funny about a naked egg?", which prompted more giggles. After the students settled down, we reviewed the scientific process and began our scientific procedures. The students really enjoyed this science experiment because they had the opportunity to be able to actively participate on a hands-on activity while making and keeping track of their observations on a daily basis.
DAY 1
On the first day of the experiment, each group had to discuss the Problem (Can an egg shell be removed without damaging the egg?) and write a hypothesis for their experiment. Next, students had to write their materials and variables in their Naked Egg Experiment Log. Once completed, they had to gather their materials using their numbered group trays. Since this is a week long experiment, the trays play an important role in keeping each group's experiment separate and easily transportable. Students then poured vinegar and water until the eggs were submerged into 2 separate cups labeled V (vinegar) and W (water). They made their first observations and answered questions in their experiment log.
DAY 2
On Day 2, students recorded their observation into their experiment logs. They then had to replace the vinegar and water with fresh vinegar and water. Students were allowed to manipulate the eggs and see if they could feel any changes. Thus, giving the students an opportunity to not just observe with their sense of sight, but also with their sense of touch.
DAY 3
Day 3 is by far the most exciting day for the students. On this day, students really get to observe a major change in the egg that has been submerged in vinegar for 48 hours. Students favorite part is when they get to remove the egg from the vinegar and bounce it on the table. Of course, be prepared for any mishaps. Out of 5 groups, one group dropped their egg on the floor. Since this is the official last day of this particular experiment, students complete their observation and illustrations for Day 3 and answer the observation questions. They also complete the conclusion and revisit their group's hypothesis.
DAY 4
As an extended activity, we developed a new hypothesis regarding what would happen to our "naked" egg if placed in corn oil. After 48 hours of our naked egg being submerged in corn oil, this is what students observed. It gave me the opportunity to discuss osmosis with the class. We were also able to reverse this process by placing the egg back into a cup of water.
This Experiment is definitely a keeper!
(If you don't mind the smell of vinegar in your classroom.)
