Science Buddies: "Ask an Expert"

My 3rd grade granddaughter just finished this project and all six of her eggs gained weight in grams after boiling. Four of the six eggs gained exactly 1.7 grams over their original weight, which was interesting in itself, and the other 2 gained approximately 1.3 grams after boiling. We ran the hot, boiled eggs under cold water until we could handle them and then immediately weighed them. We also peeled them right after weighing to see the additional water that had seeped in through the pores before there was time for the water to evaporate out.
The one question I have is, can anyone explain why 1.7 gms. seemed to be the weight the majority of the eggs gained? We are trying to figure out if maybe those 4 eggs came from the same hen and consequently had the same shell structure, or if there is probably no correlation. Any thoughts would be appreciated. The project was a great idea and we thank this site for posting ideas for students to choose from. No one else at her elementary school fair had anything similar to this project and my granddaughter took 1st place in her category. She will be the first third grader this school has ever sent on to district. She is now hooked on science fair and is vowing to do a project for years to come. Thank you for sparking her interest in science and helping her develop the scientific side of her brain.

Hi devans,

First, congratulations to your granddaughter! I am glad that she is hooked on science fairs now.

My guess as to why you got around 1.3-1.7 grams is that that is the approximate weight of water that fits into the hollow space at the end of the egg. The eggs in a given dozen are unlikely to have come from the same hen--hens generally only lay one egg per day, so all 12 eggs should be from different animals. However, the eggs are about the same size, which means that the space at the end is about the same size...and that determines how much water can be soaked up!

I am glad you and your family have had such a positive experience here!