Physical and chemical Quizlet - very important
Videos
Physical and chemical changes studyjam
Physical or chemical change Quizzes
Physical or Chemical Change Quiz 1
Physical or Chemical Change Quiz2
Interactive lesson
Flashcards
Games
Reactions & Rates This site is a little more complex. It shows that you need to have a certain amount of energy (activation energy) to start a reaction. To get enough energy for the reaction to take place heat must be added.
Sites with many chemical reactions