Elemental Tales: Comic 9

The "Elephant's Toothpaste" chemical reaction is such a super-fun and CRAZY reaction that involves the rapid decomposition of hydrogen peroxide (H₂O₂) into water (H₂O) and oxygen gas (O₂).  It's a popular science experiment to do in school.  What you do first is find any kind of empty container.  Then, in that container, pour in some hydrogen peroxide (if you want a very strong reaction, use 30% or 35% concentration of H₂O₂).  Then add in some dish soap, and stir the two ingredients to mix them together.  Then, separately, you take a little bit of potassium iodide (KI), which is a powder, and add water to it so it's in aqueous solution.  Lastly, you take that solution of KI and add it to the mixture of H₂O₂ and dish soap.  And then stand back....a GIANT amount of soap foam forms very quickly and shoots out of the mixture!

Potassium iodide acts as a catalyst for this reaction.  (More specifically, it's the iodide ion from potassium iodide that acts as the catalyst.  It speeds up the reaction without being consumed in the reaction process.)  It is added to make the hydrogen peroxide decompose very quickly.  Hydrogen peroxide breaks down into water and oxygen gas.  As a small amount of hydrogen peroxide generates a large volume of oxygen, the oxygen quickly pushes out of the container.  The soapy water traps the oxygen, creating bubbles, and turns into foam.

Potassium iodide is not the only catalyst that can be used for this reaction.  Yeast or sodium iodide can also be used as the catalyst.  Also, food coloring is an optional ingredient.  You don't have to use food coloring if you don't want to, but people often like to add food coloring to the mixture before they add the catalyst, so that the soap foam gets created in a specific color (or colors, if you add more than one food color).  However, in this comic, blue food coloring was added to the mixture not because of the soap foam, but so that the mixture looked like regular pool water, therefore fooling Sulfur and Selenium into thinking that pool water was still underneath them when they were woken from their nap.

Earlier in the comic, Potassium enters the pool water by herself (without chemically bonding to anyone else) for a while.  I needed to think of a way she could touch water by herself without exploding (since she's an alkali metal).  So I thought of this idea:  in my series, the Alkali Metals can temporarily protect themselves from water by covering their whole bodies in a hydrophobic ("water-repelling") substance.  The hydrophobic substance can be a variety of things...anything that's hydrophobic.  In real life, there are many things that have hydrophobic properties (alkanes, oils, fats, waxes, some plant leaves, etc.).  Alkali metals are often stored in mineral oil to protect them from moisture and oxygen in the air.  There are also many products that you can buy in stores that have superhydrophobic properties, and you can apply those products to various things (clothes, electronics, shoes, furniture, etc.) to protect those things from water.