Properties of Matter

ChemistryTuesday Sept. 2nd, 2008

What is Matter?What is Matter?

• Write down some words that describe matter in your notes

• Matter is:• EVERYTHING!• All around us• Makes up all the objects we see

and interact with

• Write down some words that describe matter in your notes

• Matter is:• EVERYTHING!• All around us• Makes up all the objects we see

and interact with

What properties does matter have?

What properties does matter have?

• Physical state• Solid- fixed volume & fixed shape• Liquid- fixed volume & variable shape• Gas- variable volume & variable

shape

• Name something in each of these states

• Physical state• Solid- fixed volume & fixed shape• Liquid- fixed volume & variable shape• Gas- variable volume & variable

shape

• Name something in each of these states

Physical PropertiesPhysical Properties

• Physical properties are properties that can be measured WITHOUT changing the nature of the substance

• List some examples of physical properties:• Density• Shape• Color• Size• Mass

• Physical properties are properties that can be measured WITHOUT changing the nature of the substance

• List some examples of physical properties:• Density• Shape• Color• Size• Mass

Density ReviewDensity Review

• What is the formula of density?• D = M/V

• M= mass• Mass is the quantity of matter in an object• How is mass different from weight?

• Weight is the force produced on a mass due to gravity

• V= volume• Volume is the space an object occupies

• What is the formula of density?• D = M/V

• M= mass• Mass is the quantity of matter in an object• How is mass different from weight?

• Weight is the force produced on a mass due to gravity

• V= volume• Volume is the space an object occupies

Density Review cont.Density Review cont.

• What are the units of density?• g/mL• g/cc• g/cm3

• Density is a RATIO!• Is the density of an object

always the same?• Yes! Density is a physical

property of a substance

• What are the units of density?• g/mL• g/cc• g/cm3

• Density is a RATIO!• Is the density of an object

always the same?• Yes! Density is a physical

property of a substance

Physical ChangePhysical Change

• A physical change is a change that affects only the physical properties of a substance

• List some physical changes in your notes• Evaporation• Melting• Boiling

• A physical change is a change that affects only the physical properties of a substance

• List some physical changes in your notes• Evaporation• Melting• Boiling

Chemical PropertiesChemical Properties

• Chemical properties can only be observed by changing the chemical composition of the substance (usually through interaction with another substance)

• List some examples of chemical properties• Flammability• Reactivity• Toxicity

• Chemical properties can only be observed by changing the chemical composition of the substance (usually through interaction with another substance)

• List some examples of chemical properties• Flammability• Reactivity• Toxicity

Chemical ChangeChemical Change

• A change that produces one or more NEW chemical substances (bonds between atoms are rearranged).

• Chemical changes are usually not reversible

• List some examples• Formation of a new compound

• Burning a log• Photosynthesis

• A change that produces one or more NEW chemical substances (bonds between atoms are rearranged).

• Chemical changes are usually not reversible

• List some examples• Formation of a new compound

• Burning a log• Photosynthesis

What does this have to do with Chemistry????

What does this have to do with Chemistry????

• Chemistry is the study of matter and its properties

• Chemists study the structure and composition of matter

• Chemists study changes in the structure and composition of matter

• Chemists want to know WHY changes in matter occur

• Chemistry is the study of matter and its properties

• Chemists study the structure and composition of matter

• Chemists study changes in the structure and composition of matter

• Chemists want to know WHY changes in matter occur

Chemistry DefinitionsChemistry Definitions

• Chemical- any substance with a definite composition

• Chemical reaction (rxn)- the process by which elements or compounds interact to form new substances

• Chemical- any substance with a definite composition

• Chemical reaction (rxn)- the process by which elements or compounds interact to form new substances

Writing chemical reactionsWriting chemical reactions

• Reactants Products

• Reactants- are present at the beginning of a reaction

• Products- are the result of a reaction

• Reactants Products

• Reactants- are present at the beginning of a reaction

• Products- are the result of a reaction

How do you know when a chemical reaction has

occurred?

How do you know when a chemical reaction has

occurred?

• Write some guesses in your notes!

• This is what our next lab is about!!

• Write some guesses in your notes!

• This is what our next lab is about!!

Verification of a Chemical Rxn

Verification of a Chemical Rxn• A gas is produced- bubbles will be released

• Example?• Baking soda & vinegar

• A precipitate (solid) is formed – a solid is formed from two liquids

• Example?

• Heat is produced OR absorbed • Examples?

• Endothermic – energy is absorbed (feels cooler)

• Exothermic – energy is released (feels warmer)

• A gas is produced- bubbles will be released• Example?

• Baking soda & vinegar

• A precipitate (solid) is formed – a solid is formed from two liquids

• Example?

• Heat is produced OR absorbed • Examples?

• Endothermic – energy is absorbed (feels cooler)

• Exothermic – energy is released (feels warmer)

Verification of a rxn cont.Verification of a rxn cont.•Light is emittedExample?

•A color change in the reaction system.• Do not confuse this with a dilution or

blending of color• Making Kool-Aid is not a chemical

reaction!

Keep in mind that some of these observations can be made during physical changes!

•Light is emittedExample?

•A color change in the reaction system.• Do not confuse this with a dilution or

blending of color• Making Kool-Aid is not a chemical

reaction!

Keep in mind that some of these observations can be made during physical changes!