Properties of MatterProperties of MatterChapter 17 Section 2Chapter 17 Section 2

Physical Properties and Physical Properties and Changes.Changes.

Physical PropertiesPhysical Properties

Any characteristic of a material that you Any characteristic of a material that you can observe or attempt to observe can observe or attempt to observe without without changing the identity of the substance that changing the identity of the substance that makes up the material makes up the material is a is a physical physical property.property.

ExamplesExamples

Physical changes include:Physical changes include:

ColorColor

SizeSize

ShapeShape

Melting pointMelting point

Boiling pointBoiling point

Explanation Explanation

What an object looks like, i.e., an apple, What an object looks like, i.e., an apple, tennis ball, a rock. – tennis ball, a rock. – Physical DescriptionPhysical Description

AppearanceAppearance – How the object reacts with – How the object reacts with the things around it.the things around it.

If you knocked over corn syrup, the high If you knocked over corn syrup, the high viscosityviscosity in the liquid is a in the liquid is a physical physical property.property.

You can use the You can use the physical propertiesphysical properties to separate mixtures.to separate mixtures.

Example: Example:

Different seeds – Different seeds –

the filling in a Twinkie-the filling in a Twinkie-

or eating the icing on a cake but not eating or eating the icing on a cake but not eating the cake itself. (Thibodeaux’s 5the cake itself. (Thibodeaux’s 5thth Birthday)Birthday)

The changes in the states of matter The changes in the states of matter are examples of are examples of physical changephysical change..

The changes in the states of matter (solid The changes in the states of matter (solid liquid liquid gas) are examples of a gas) are examples of a physical change.physical change.

When a substance When a substance freezes, boils, freezes, boils, evaporates, or condensesevaporates, or condenses, it undergoes a , it undergoes a physical changephysical change..

More Physical DescriptionsMore Physical Descriptions

A change in:A change in:SizeSize

ShapeShape

State of matterState of matter

All are considered physical change.All are considered physical change.

Here’s what I am trying to say!Here’s what I am trying to say!

There may be changes, but the identity of There may be changes, but the identity of the element or compound does the element or compound does notnot change.change.

Example:Example:

Water – Water – If it freezes, is it still water?If it freezes, is it still water?

If it is boiling, is it still water?If it is boiling, is it still water?

If it is in the liquid state, is it still water?If it is in the liquid state, is it still water?

They are different sizes, shapes, and states, but They are different sizes, shapes, and states, but still high quality Hstill high quality H22O!!!O!!!

Example #2Example #2

IRON – IRON –

When you heat iron, it turns red or white. When you heat iron, it turns red or white. Even though there is a color change, it is Even though there is a color change, it is still iron.still iron.

DistillationDistillation

DistillationDistillation is a process for separating is a process for separating substances in a mixture by evaporating a substances in a mixture by evaporating a liquid and recondesing its vapor.liquid and recondesing its vapor.

It is usually done in a laboratory using an It is usually done in a laboratory using an apparatus. apparatus.

The liquid is boiled then condensed in a The liquid is boiled then condensed in a tube leaving the solid material behind.tube leaving the solid material behind.

Picture of DistallationPicture of Distallation

Water is not all equal.Water is not all equal.

This is how some water purifiers make This is how some water purifiers make there distilled water.there distilled water.

There are water plants next to the ocean There are water plants next to the ocean that takes the sea water, distills it, leaving that takes the sea water, distills it, leaving the salt behind and fresh purified water to the salt behind and fresh purified water to be sold.be sold.

Example:Example:

Two liquids with different boiling points can Two liquids with different boiling points can be separated this way.be separated this way.

This is how they separate natural gas from This is how they separate natural gas from oil.oil.

Chemical Properties and Chemical Properties and ChangesChanges

The tendency of a substance to burn, or its The tendency of a substance to burn, or its flammability, is an example of a flammability, is an example of a chemical chemical propertyproperty because burning produces: because burning produces:

A New Substance!!!!!!!!A New Substance!!!!!!!!During a chemical change.During a chemical change.

Chemical PropertyChemical Property

A A chemical propertychemical property is a characteristic of a is a characteristic of a substance that indicates whether it can substance that indicates whether it can undergo a certain chemical change.undergo a certain chemical change.

Examples:Examples:

Lighter fluidsLighter fluids

Medicine – bottles are dark because light Medicine – bottles are dark because light will change them chemically if exposed too will change them chemically if exposed too long.long.

Example #2Example #2

If you burn something, the bad odor is the result If you burn something, the bad odor is the result of a chemical change. of a chemical change.

If you smell rotten eggsIf you smell rotten eggs

The rust on a bike – The rust on a bike –

New substance = chemical changeNew substance = chemical change(write this down)

This is what I am trying to say!!This is what I am trying to say!!

Easy way to remember:Easy way to remember:

If you can’t change it back to its original If you can’t change it back to its original state, then it was a state, then it was a chemical changechemical change, but , but if you can, then it was a if you can, then it was a physical changephysical change..

Chemical ChangesChemical Changes

A rapid release of energyA rapid release of energy

Heat, Light, and Sound are all clues that Heat, Light, and Sound are all clues that changes have occurred.changes have occurred.

Chemical ChangesChemical Changes

Chemical Changes clues: Chemical Changes clues: HeatHeatCoolingCoolingOr the formation of bubblesOr the formation of bubblesThe creation of solids in a liquid The creation of solids in a liquid

All these are helpful indicators that a All these are helpful indicators that a reaction has taken placereaction has taken place

WeatheringWeathering

Question – Are the forces that cause rocks Question – Are the forces that cause rocks to split, deep canyons to be carved out, to split, deep canyons to be carved out, sand dunes shift, or curious limestone sand dunes shift, or curious limestone formations caused by physical weathering formations caused by physical weathering or chemical weathering.or chemical weathering.

PhysicalPhysical

Large rocks split when water seeps into Large rocks split when water seeps into the small cracks and freezes.the small cracks and freezes.

Remember what happens to water when it Remember what happens to water when it freezes.freezes.

It exapandsIt exapands

PhysicalPhysical

The new rock that is exposed is the same The new rock that is exposed is the same as the original.as the original.

It was physicalIt was physical

ChemicalChemical

Solid calcium carbonate does not dissolve Solid calcium carbonate does not dissolve easily in water. However, when the water easily in water. However, when the water is slightly acidic, calcium carbonate reacts. is slightly acidic, calcium carbonate reacts. It changes into a new substance, calcium It changes into a new substance, calcium hydrogen carbonate, which does dissolve hydrogen carbonate, which does dissolve in water. This is considered a chemical in water. This is considered a chemical change because the identity of the calcium change because the identity of the calcium carbonate changes.carbonate changes.

The Conservation of MassThe Conservation of Mass

The Conservation of Mass – The Conservation of Mass –

According to the Law of Conservation of According to the Law of Conservation of Mass, the mass of all substances that are Mass, the mass of all substances that are present before a chemical change equals present before a chemical change equals the mass of all the substances that remain the mass of all the substances that remain after the change.after the change.

Matter is neither created nor destroyed.Matter is neither created nor destroyed.

It just changes in a chemical reaction.It just changes in a chemical reaction.