Alien Eggs
Submitted By: Stephanie Lum
Overview
Awesome, really easy, chemistry experiment in which you mix a solution of alginic acid and a
solution of calcium chloride together to get a solid, colourful, gooey alien egg! Children will learn
about solutions, monomer and polymers.
Topic Area(s)
Chemistry
Age
8-13
Cost
$0.50
Time
1 hr
Complexity
Preparation= 2
Execution= 1
Objective
To learn about
solutions,
monomers/pol
ymers
Hook
This project is super fun because you mix two liquids together to get a solid, colourful, gooey alien
egg!
Necessary Background Information
What is a solution?
A solution is a mixture of different substances mixed together. A solution could be in the form of a
gas, liquid or solid. Today, we will look specifically at a liquid solution. Ex: take a package of koolaid and mix it with water
What is a solute?
A solute is the substance dissolved in our liquid. This would be the kool-aid.
What is a solvent?
Liquid the solute is dissolved in. This would be the water.
Polymers are very long molecules consisting of small repeating subunits (called monomers),
connected by chemical bonds. The term is derived from the Greek words: polys meaning many, and
meros meaning parts. The monomers are linked to each other during a chemical reaction called
polymerization. These chains are connected to each other by cross-links.
In this experiment, we will carry out a chemical reaction using calcium chloride solution to alginic
acid solution. Alginic acid is a carbohydrate that can be found in brown seaweed (kelp). When the
alginic acid is added to the calcium chloride, calcium alginate is formed. Alginic acid is the
polymer and calcium chloride is the cross-linker. Calcium alginate is the thick gel polymer which is
the alien egg! This reaction cannot be reversed using heat.
Calcium alginate can also be used to produce artificial plant seeds.
Materials
Per pair of children:
 1 g of alginic acid, sodium salt
 2 g calcium chloride
 150 mL water
 Few drops of food colouring
 Two 250 mL beakers
 2 small ziplock bags
 1 popsicle stick
Safety Considerations
Do not eat the alien eggs.
Procedure
Each pair of children:
1. In a beaker, mix 2g of calcium chloride with 100mL water until dissolved. (Use a popsicle
stick to stir)
2. In another beaker, mix 1g of alginic acid sodium salt with 50 mL water. (Use a popsicle stick
to stir) Add a few drops of food colouring to this beaker.
3. Pour some of the alginic acid solution into the beaker with the calcium chloride and
immediately, an alien egg is formed!
4. Let each child take home some alien eggs in a ziplock bag.