Describing Describing MatterMatter

Physical PropertyPhysical Property

Any characteristic of a Any characteristic of a material that you can material that you can observe without observe without changing the changing the substances that make substances that make up the materialup the material

Examples of Physical PropertiesExamples of Physical Properties

ColorColor ShapeShape SizeSize Melting PointMelting Point Boiling PointBoiling Point FlexibilityFlexibility MagneticMagnetic SmellSmell DensityDensity

Por EjemploPor Ejemplo

You might describe the You might describe the appearance of an iron appearance of an iron nail as: nail as:

A pointy ended cylinderA pointy ended cylinder Made of a gray-colored Made of a gray-colored

solid.solid.

Physical propertiesPhysical properties are are measureablemeasureable

For ExampleFor Example

If you had a soft drink If you had a soft drink in a cup, you could in a cup, you could measure its volume and measure its volume and temperature, and temperature, and describe its odor. describe its odor.

Each of these is a Each of these is a physical propertyphysical property

Physical ChangePhysical Change

If you break a piece of If you break a piece of chalk, its size and shape chalk, its size and shape have changed. have changed.

But you have not But you have not changed the identity, changed the identity, the chemical the chemical consistency, of the consistency, of the substance ….it is still substance ….it is still chalk, still made chalk, still made entirely of chalk entirely of chalk molecules.molecules.

Physical Change IIPhysical Change II

The changes in state The changes in state (solid (solid liquid liquid gas gas

plasma)plasma) are all example of are all example of physical changes. physical changes.

When a substance When a substance freezes, boils, freezes, boils, evaporates, sublimes, or evaporates, sublimes, or condenses, it undergoes condenses, it undergoes physical changesphysical changes. .

Physical ChangesPhysical Changes

A change in A change in sizesize, , shapeshape, or , or statestate of of mattermatter

Physical properties can Physical properties can be used to separate a be used to separate a mixturemixture

Chemical ChangeChemical Change Burnt toast, burned soup, and Burnt toast, burned soup, and

burned steak all smell burnt. burned steak all smell burnt.

The smell is different from the The smell is different from the smell of bread, soup, or steak.smell of bread, soup, or steak.

The odor is a clue that a new The odor is a clue that a new substance has been producedsubstance has been produced

A change of one substance into A change of one substance into a different substance is a a different substance is a chemical changechemical change

Examples of Chemical ChangeExamples of Chemical Change

When iron is exposed to When iron is exposed to oxygen and water, the oxygen and water, the iron reacts and forms a iron reacts and forms a new substance: new substance: RustRust

Gasoline is burned, Gasoline is burned, forming carbon dioxide forming carbon dioxide and water: Both are new and water: Both are new substancessubstances

Chemical PropertiesChemical Properties

a characteristic of a a characteristic of a substance that substance that indicates whether it indicates whether it can undergo a certain can undergo a certain chemical change.chemical change.

Ex: the tendency of a Ex: the tendency of a substance to burn is a substance to burn is a chemical propertychemical property