Today’s Wonder of the Day was inspired by Stella. Stella Wonders, “How do bath bombs work?” Thanks for WONDERing with us, Stella!

Who doesn’t love bubble baths? They make bath time a blast! You can have fun blowing bubbles into the air, building bubble towers in the tub, even giving yourself a bubble beard. Of course, there are many other ways to make bath time both fun and luxurious. Today’s Wonder of the Day is about one in particular—bath bombs! 

What’s so great about bath bombs? Many people enjoy the scents they add to a bath. Most of them also add fun colors to the water, and some even contain flowers or other small aromatics. Some bath bombs also make for bubbly bath water, but most offer a fizzing effect instead.

What makes bath bombs fizz in warm water? It has to do with the chemistry of how they’re made. The ingredients interact with each other and water to produce the effects people expect from these scented spheres.

So, what exactly are bath bombs made from? Many people and companies have their own recipes, but they often include the same basic ingredients: baking soda, citric acid, and cornstarch. These work together to form the bath bomb and make it fizz in water.

Baking soda and citric acid both dissolve easily. When the two interact in water, they produce carbon dioxide. This gas causes the fizzing bubbles you see after dropping a bath bomb in a tub of water. Cornstarch slows this reaction by binding to both baking soda and citric acid. It causes the fizzing to last longer.

Of course, many bath bombs contain more than these three ingredients. Most have dyes and scents that are also released when the bomb dissolves. These produce the colors and aromas that people expect from bath bombs. They may also include oils and epsom salts. 

Many companies, such as LUSH, specialize in making unique bath bombs from a variety of ingredients. However, people also enjoy creating their own at home. All you need to get started is the basic ingredients, and colors or scents you want to add, and a bath bomb mold. Everything can be combined and pressed into the mold to make a custom bath bomb.

No bathtub? No problem! Shower bombs are also an option. They’re full of fragrance and fizz just like a bath bomb. When shower bombs meet water, they dissolve into a thick foam that can be used as soap.

How do you like to make bath time more fun? Do you prefer bath bombs or bubbles? Maybe instead you have a favorite type of music to listen to. It can be fun to find your own ways to make this time of day special.

Standards: NGSS.PS1.A, NGSS.PS1.B, CCRA.R.1, CCRA.R.2, CCRA.R.4, CCRA.R.10, CCRA.W.2, CCRA.W.4, CCRA.L.1, CCRA.L.2, CCRA.L.3, CCRA.L.6, CCRA.SL.1

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