One of the three things I lerned about is: I learned about the fact that most acids you eat on a normal basis.  There is a pH scale that tells you if they are dangerous or not. Another thing I learned is that you see physical and chemical changes everyday. The last thing I learned about is if you mix certain particles together it becomes heat. The thing I liked about this chapter is the lab we did where we mixed the particles together and it became heat. The thing I didn't like about this chapter is it didn't have enough experiments and it wasn't interesting.

But I wonder what chemical is the most dangerous.