Matter and Change

Part 1 – Properties of Matter

TAKS student expectation

• Integrated Physics and Chemistry (8) Science Concepts. The student knows that changes in matter affect everyday life. The student is expected to:– (A) distinguish between physical and

chemical changes in matter such as oxidation, digestion, changes in states, and stages in the rock cycle; and

Here’s what you have to do if you want to pass this part of

the TAKS:

1. Distinguish between physical and chemical properties.

Here’s what you have to do if you want to pass this part of

the TAKS:

1. Distinguish between physical and chemical properties.

Characteristics of a substance can be classified as physical properties or chemical properties. Which of the following is a chemical property?A Boils at 56ºCB Tastes sourC Has a density of 2.9 g/cm3D Reacts with acid to produce hydrogen gas

Sample Question

Source: Reviewing Chemistry TAKS.

Properties and Changes in Matter

• Every substance has characteristic properties.

• Chemists use these properties to distinguish between substances and separate them.

Extensive vs. IntensiveProperties

Properties are either extensive or intensive.

Extensive Properties

depend on amount of matter present

volume, mass, and

amount of energy in a substance

Intensive Properties

do not depend on amount of matter

presentmelting point, density,

ability to conduct electricity, and percent

composition

Properties of One Penny

Properties• Metal

• Composed of 2.5% copper and 97.5% zinc

• Mass – 2.50 grams

• Volume – 0.442 mL

• Density – 5.66 g/mL

Properties of Many PenniesProperties• Metal

• Composed of 2.5% copper and 97.5% zinc

• Mass – 2500 grams(1000 pennies x 2.5 g)

• Volume – 442 mL(1000 pennies x.442mL)

• Density – 5.66 g/mL

One Thousand Pennies

Extensive vs. Intensive Properties

WHICH PROPERTIES REMAINED THE SAME?

• Metal

• Percent Composition

• Density

The intensive properties remained the same because they do not depend on

the amount of pennies present.

Extensive vs. Intensive Properties

WHICH PROPERTIES CHANGED?• Mass

• Volume

The extensive properties changed because they do depend on the amount of pennies present.

Property Types• There are 2 major categories

that all properties of matter fall into

Physical Properties

Physical properties are characteristics that can be observed or measured without changing the identity of a substance.

They can be observed by using the five senses.

Physical Properties• Cross between a lab

and a poodle

• Size of a lab

• With the curly hair of a poodle

• Can be black, yellow, brown, or white

• Tail of a lab

What are What are the the

physical physical properties properties

of a of a labradoodlelabradoodle

??

Chemical PropertiesChemical properties relate to a

substance’s ability to undergo changes that transform it into different

substances.

Examples of chemical properties:

Conductivity -ability to conduct electricity

Flammability – ability to ignite

Electronegativity – the ability to retain electrons

Density – a Property of Matter

Density – a ratio that compares the mass of an object to its volume.

The density of every pure substance in the world is unique.

Calculating Density

The formula for calculating

density is given on your TAKS formula chart,

so you must know how to use

it

Vm

D

volume

massDensity

Sample Question

Source: Grade 11 TAKS Information Book

Sample Question

Source: Spring 2003 Exit TAKS

Sample Question

Source: Spring 2003 Exit TAKS

Sample Question

Source: Spring 2003 Exit TAKS

Sample Question

Source: Spring 2003 Exit TAKS

Sample Question

Source: Spring 2003 Exit TAKS

Sample Question

Source: Spring 2003 Exit TAKS

Remember to duplicate

Sample Question

Source: Spring 2003 Exit TAKS

Sample Question

Source: Spring 2003 Exit TAKS

Sample Question

Source: Spring 2006 10th TAKS

Sample Question

Source: Spring 2006 10th TAKS

Part 2 – Changes in Matter

Physical ChangeA change in the physical appearance of a

substance that does not change the identity of the substance.

LIQUID

SOLID

GAS

Physical ChangesPhase Change – physical change from

one state to another

LIQUIDBetween 0°C and

100 0°C

SOLIDBelow 0°C

GASAbove 100°C

Only the temperature changes

Still H2O in every form!!!

Physical Changes• Examples of physical changes:

Crushing an aluminum can

Cutting your hair

Shredding paper

Chemical ChangesChemical changes, or chemical reactions, occur

when one or more substances is converted into another substance.

Original atoms are preserved

New substances are formed

Different chemical composition than original substance

Chemical ChangesChemical changes are chemical reactions.

Indicated by a number of signs

• formation of a gas,

• formation of a solid, or precipitate

• change in temperature

• evolution of heat and light

• Change in color

• Change in odor

Chemical Changes• When iron (Fe) rusts, you can see it

happen over a long period of time.

• The actual iron molecules change their structure as they react with oxygen and are oxidized.

Chemical Changes• Examples of chemical changes:

Milk souring

Grass growing

Frying an egg

Energy Transfer• All changes (physical and chemical) involve some

transfer of energy.

• Body uses energy from chemical reactions to digest food.

• Weather involves a transfer of energy to evaporate water in the atmosphere.

• Therefore, the study of matter also involves the study of energy.

Summary• Extensive Properties

• Intensive Properties

• Physical Properties and Changes

• Chemical Properties and Changes

• Transfer of Energy