Chemical and Physical Properties of Matter

Matter Matter is Different matter has different

Physical Properties A physical property Some physical properties are Ex – Will your books fit into you backpack? You are using the physical property of volume.

Physical Properties Thermal conductivity – State of Matter – Density –

Physical Properties Solubility – Ductility – Malleability –

Physical Changes A physical change Ex. A piece of silver is pounded and molded into a heart-shaped pendent. (it is still silver) Ex. – changing from a liquid to a solid (or any phase change) Ex. – crushing an Aluminum can. It is still aluminum, just the shape has changed. Ex – Sawdust – it is still wood – only in smaller pieces.

Chemical Properties Chemical properties Chemical changes occur when Ex. – burning wood, tarnishing, and rusting

Chemical Properties Flammability – Reactivity – Chemical reactions involve two main kinds of changes that you can observe –

Physical Properties vs. Chemical Properties ___________________– physical property being changed is shape ___________________– chemical property being changed is composition (iron is reacting with oxygen to make iron oxide - rust) ___________________– physical change of state ___________________– chemical change – it is not alcohol any more.

How do I know that a chemical change is taking place? There will be a change in odor and/or color, heat will be either absorbed or released, the substance will bubble or fizz, light or sound may be given off. Ex.

Changes in Energy As matter changes, _____________________. A change in energy occurs during a chemical reaction. An endothermic reaction Many endothermic reactions occur when heat is constantly added. (Ex: egg frying) In other words…they need energy to keep going.

Changes in Energy An exothermic reaction After an exothermic reaction, the products have ______________________________. (Ex: the burning of fuel) The reaction between fuel and oxygen in an airplane engine releases energy, mostly in the form of heat. The expansion and movement of the gases out of the plane exerts a force that moves the plane forward.

Can physical and chemical changes be reversed? Physical changes are _________________. You can melt ice and then freeze it again. Chemical changed are___________________. When a firework explodes it would be almost impossible to put the materials back together.