Why do we combine substances in the first place?

So students are understanding that mass can't be created nor destroyed, but why might we even combine two or more substances together in the first place?  

"To see what happens!"

"To make something new."

"To create something you need."

Yup!  You're right!  We started discussing why substances might be combined, such as in baking, in medicine, or for technology purposes.  So our last lesson in our chemical tests unit involved making mixtures for an intended purpose:  to make a sole for an athletic shoe!

Combining various chemicals gave us very different results...and students compared the results in a variety of tests.  Check out their awesome work...and if you see them, ask them what shoe sole recipe they recommend!