Presentation on theme: "4 Types of Chemical Reactions 6 th Grade Science."— Presentation transcript:
4 Types of Chemical Reactions 6 th Grade Science
Physical Changes and Chemical Reactions: Physical Change Physical changes are about energy and states of matter.states of matter. Melting an Ice-Cube Chemical Reaction Chemical changes happen on a molecular level when you have two or more molecules that interact and create a new molecule or two.
Physical or Chemical? Crushing a canMelting an Ice Cube
Physical or Chemical? A Rusty NailThe Statue of Liberty
4 types of Chemical Reactions 1. Synthesis Reaction A + B AB Reactants A and B combine chemically to form a more complex molecule, AB. AB then stores energy in its bonds.
4 Types of Chemical Reactions 2. Decomposition Reactions AB A + B The molecules AB is chemically broken down to smaller molecules, and in doing so, energy is released.
4 Types of Chemical Reactions 3. Exchange Reactions AB + CD AD + CB These reactions involve both synthesis and decomposition reactions. The reactants exchange parts to yield new chemical compounds.
4 Types of Chemical Reactions 4. Reversible Reactions A + B AB Chemical bonds can be made and they can be broken depending on the requirements of the body. Example: Glycogen molecules can be synthesized from glucose molecules for storage in liver cells, and glycogen can be decomposed to glucose by the liver during periods of low blood sugar.