Physical and Chemical Properties

Physical Property Observed without changing the composition of the substance Substance undergoes a change but is still the same substance after it happens Ex: if you break a pencil in half, you have made a change to it but it is still a pencil even after it is broken

Types of Physical Properties Viscosity Conductivity Malleability Hardness Magnetism Melting/Boiling Point Density Color

Viscosity resistance of a substance to flow Ex: water = low viscosity (flows easily) Ex: honey = high viscosity (does not flow easily)

Conductivity Allowing heat/electricity to flow Ex: metal = high conductivity Ex: wood = low conductivity

Malleability Ability to be hammered without shattering Ability to be hammered into a thin sheet Ex: tin = high malleability (can be hammered into a thin sheet without it shattering) Ex: glass = low malleability (easily shatters when hammered)

Melting and Boiling Points Melting Point – temperature at which the substance changes from solid to liquid Boiling Point – temperature at which the substance changes

Density Ratio of mass to volume

Two Ways to PHYSICALLY Separate Mixtures Distillation – separates materials based on boiling points Filtration – separates materials based on particle size

Physical Change The appearance changes but the composition DOES NOT change It always remains the SAME SUBSTANCE after the change happens!

Chemical Property Ability to change the composition of matter Substance undergoes a change and is no longer the same substance Ex: Your body contains a substance called catalase. When you put hydrogen peroxide (H2O2) onto an open wound it reacts with the catalase. The catalase breaks the hydrogen peroxide down into water (H2O) and oxygen (O2)

Types of Chemical Properties Flammabiity Reactivity Ability to burn in the presence of oxygen How readily a substance chemically combines with another

Chemical Change Occurs when a substance reacts to form a new substance Signs of a chemical change Change in color Production of gas Formation of a precipitate (solid that forms from a reaction) Ex: Chunks that form when milk sours Rusting Oxidation