Spring fever is the air and our young students are excited about preparing for Easter or other spring celebrations. Many students are learning about farms and reading spring stories this time of year. As you plan spring related stories, crafts, and activities – why not put in a few science experiments with eggs to challenge your students’ thinking? Take a look at my fun eggs-periments that are egg-cellent for your students to get their little hands on!
Take advantage of the math skills students can practice as they measure and weigh an egg. My students used a tape measure to measure around the egg and used a grid to see how many squares the egg covered. Students love measuring the water before and after an egg has been placed in the cup.
Raw or Hard Boiled?
I like to give my students real world science problems. Instead of just telling them they need to figure out which egg is raw and which is hard boiled, I try to make up a more realistic story task.
For example: “Boys and girls. You are not kindergarteners right now. You are scientists! We have a problem and we need your help. A delivery truck just pulled up to our local grocery store from the farm to deliver eggs. When they were unloading the eggs, the people that work at the store asked, “Which eggs were the raw ones and which were the hard boiled eggs?” Someone forgot to mark the egg containers! The grocery store can’t sell the eggs until they are marked so people buy the right type of egg. They need your help to figure out which eggs are the hard boiled ones and which are the raw eggs.”
After hearing the story and buying into this purposeful task, students are even more eager to perform their experiments. They take their job very seriously because of the important problem they have been asked to solve.
Each table was given two eggs, labeled with a 1 or a 2. Students work together to try out the different tests listed on our recording sheets. (Here is a copy of our experiment recording sheet.) My students had a great time rolling, smelling, and shaking their eggs! When the paper asked which egg they thought was raw, I had mixed opinions. After each table discusses their thinking, the groups agreed on which egg they thought was raw or hard boiled. Fortunately for me, they were correct!
The next step is the most fun for students. They had to crack the eggs they thought was hard boiled. You should have heard their screams as each group realized they picked the correct egg! Afterword, I cracked each of the other eggs to prove to the kids that they really had a raw egg as well.
It is always important to discuss the science behind it. We determined that the best two tests were the shake test and the spin test. When most kids shook the eggs they were able to hear the yolk move in one egg. We also discovered that the hard boiled egg will spin faster and easier then the raw egg because the yolk is now a solid.
Will the Egg Float or Sink?
One of the science concepts students are expected to understand is whether objects float or sink. In the past we have done experiments to learn more about this concept. For this experiment, we worked with fresh water and salt water to see if that made a difference in eggs floating or sinking.
Students started by making predictions and then recorded their observations with drawings and labels as they did the experiment. They were so excited to see that adding salt to the water made the egg float! We discussed the science behind salt water and how it is more dense then fresh water making the egg float.
Fresh Egg or Rotten Egg?
After doing the float or sink experiment, all of my students now think all raw eggs will float in fresh water all the time. Next week, I will challenge their thinking by having them try an experiment like this again. This time they will have two eggs and they will not know that one is a fresh raw egg and the other is a rotten egg. They will be very confused as they see one egg sink and the other float. The fresh egg sinks, while the rotten egg floats.
Students need to use the prior experiments to figure out the difference between the eggs. I will observe their thinking to see what tests we need to try out again in order to help students determine the difference between the eggs. I will encourage them to think about which tests helped us to figure out which egg was raw and which was hard boiled. Once they try to shake or spin the eggs, they will realize they are both raw eggs. Then they will need to try other tests and form their hypothesis. We will finish by cracking the eggs outside. Once the eggs are cracked and students use their sense of smell, they will be able to figure out that one was rotten.
Are Egg Shells Strong or Do They Break Easily? (Teacher demonstration)
As we were reading the book, From Egg to Chicken and learning about the life cycle of the chicken, we noticed the book said egg shells are hard. I asked my students if they thought egg shells were hard. Most of their responses were yes. Then I asked them why did I keep telling them to be careful with the eggs the day before? They responded that they will crack. We thought about this for a while and became very confused. Students started to think that once the eggs were taken from the hen they became softer. This was a perfect time for our next experiment!
This experiment has been one of my favorites because of the students’ reactions and the learning that occurred. To start I handed out the experiment recording sheet with the first question asking the students if they thought egg shells were strong or broke easily and why. There were mixed responses and great explanations by my students. Some kids said they were strong because the hen has to sit on them. Other said they broke easily because they broke an egg the day before and it wasn’t difficult.
The next part of the experiment was telling the students that I was going to squeeze an egg as hard as I can. I asked them if they thought it would break and all of my students thought it would. They became very excited at the thought of me squeezing an egg and breaking it all over the place. Many students suggested doing it over a bowl which we did.
My students were shocked as they watched me squeeze as hard as I can over the document camera and the egg did not break. They asked me to try squeezing with two hands and the same results happened. After the amazement of seeing this they decided that egg shells were hard and strong.
After doing this part of the experiment I had many convinced that an egg shell was strong. I had to ask them why people always tell them to be careful with eggs because they break easily. This is when I explained the science behind the shape of the egg and pressure. When an egg is squeezed pressure is even around the whole egg. This is important because when the hen sits on the eggs it needs to be strong enough not to break. When the baby chicks are ready to hatch, the egg has to be able to break easily and let the chick out. When a chick is pecking they are only putting pressure on a part of the egg and not the whole egg at the same time. This is when I show them how I can crack the egg with one finger if I just press a little.
After explaining and demonstrating, my students decided that the egg shell was both strong and easy to break depending on the pressure.
Next week we will be continue some more egg experiments, including putting an egg in vinegar and letting the shell dissolve off. We will also finish with dying eggs as a festive way to end our egg unit.
I hope as you are learning about farms or preparing for spring you are able to incorporate some of these egg experiments into your unit. They are a ton of fun and allow students to really think and test out their thinking. As always I would love to hear from you about what you are doing in your classrooms.