Making Science Girlie

These days Brownies earn both Keys and merit badges. Keys are worked on and earned together as a group. We work on four Keys a year to make sure the girls can earn all the Keys over the two year program. 

The last couple meetings we have been working on the Key to STEM (Science, Technology, Engineering, and Math).

Specifically - Why do things go fizz, pop, or do nothing at all when mixed together? Bath bombs are the perfect way to teach the girls some basic chemistry AND have a gift to give their moms at the end-of-year mother-daughter banquet.

Before we started, we demonstrated what happens when we mix baking soda and vinegar (which contains acetic acid). They were hoping for some gigantic explosion but unfortunately they would have to settle for  some fizz and a little pop.

While that was fresh in their minds - we showed them a bath bomb and told them that is what we were going to make. After all the oohing and ahhhing, we told them the ingredients that we needed.

• Baking Soda
• Citric Acid
• Olive Oil
• Corn Starch
• Epsom Salts
• Water
• Food Colouring
• Essential Oil (we chose citrus essential oil)

After going through each ingredient it was determined that:

• Baking soda & Citric Acid make the fizz;
• Corn Starch, water & Olive Oil keep everything together but the olive oil is also good for your skin;
• Epsom salts have many benefits including; reducing stress & promotes relaxation, relieves pain & muscle cramps, eliminates toxins from the today etc.;
• Essential Oil makes it smell nice and relaxing people; and 
• Food colouring, well makes it pretty.

We had the girls work in three groups and had them mix the dry ingredients first 

Dry ingredients: 

• Baking Soda - 2 cups
• Citric Acid - 1 cup
• Corn Starch - 1 cup
• Epsom Salts - 1 cup

Afterwards we had the girls mix the wet ingredients into a mason jar to they could simply shake it to mix.

Wet Ingredients:

• Water - 1/2 tbsp
• Essential Oil - 2 tsp 
• Oil - 2.5 tbsp (I used cherry kernel, but any light vegetable oil will work.)
• Food colouring - 1 or 2 drops

Then, while stirring, slowly add small amounts of the liquid to the dry ingredients.

If the mixture starts to foam, the liquid is being added too quickly. When all of the wet ingredients have been added, the mixture should feel like damp sand. 

Now it's time to mould the bath bombs - I liberated a million or so paper cups from McDonald's (you know the ones for ketchup). I told the girls to make sure to pack the mix tightly in the paper cups. This is very important or they might not keep their shape. Benefit of the paper cups, easy for the girls to mould AND we can just peel them back revealing the beautifully crafted bath bombs.

Time to carefully remove the bath bomb from the paper cup.

We can't just give the bath bombs out to the moms looking like this. Some gift appropriate packaging is required.

Not every bath bomb wanted to be freed in one piece from the mould. There were some bath bomb casualties. They are now resting peacefully in my bathroom.  Bad news for the girls, good news for me.