BURNING A CANDLE - Kyrene School District / Best Schools ... 31... · BURNING A CANDLE •After...

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Transcript of BURNING A CANDLE - Kyrene School District / Best Schools ... 31... · BURNING A CANDLE •After...

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BURNING A CANDLE

• After melting, is the wax still

wax?

Yes, so Physical Change

• After burning, is the candle wick

still a candle wick?

No, so Chemical Change

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MR. BEAN MEETS CHEMISTRY

• As you watch the

video of Mr. Bean,

what are some

indicators of a

chemical change

(chemical reaction

that you notice)?

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SolidFixed VolumeFixed Shape

Least Kinetic Energy

LiquidFixed Volume

No fixed shapeModerate

Kinetic Energy

GasNo Fixed VolumeNo Fixed Shape

Most Kinetic Energy

Melting

BoilingEvaporating

Freezing Condensing

Sublimation

Deposition

Remember: States of matter changes are physical changes. The identify of the substance

stays the same.

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Physical and Chemical Properties of Matter

Physical Properties/Changes Chemical Properties/Changes

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Graphite — the layered structure of the carbon atoms gives graphite its physical properties.

The pattern of the atoms gives the

substance its physical properties.

Physical Properties

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Physical Properties

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Physical Changes– can be observed without changing the identity

of the substance( color, hardness, melting point & density)

– is only a change in any physical property of a substance

– matter can change from one state to another (liquid to a gas)

Some physical changes would be• boiling of a liquid• melting of a solid• dissolving a solid in a liquid • grinding or crushing• Condensation - when gas

becomes a liquid

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Physical Properties and Changes Recap

• The characteristics of a substance that can be observed without changing the identity of the substance are called physical properties.▫ Examples:

Color Shape Texture Volume Mass Density

• A physical change is any change in any physical property of a substance, not in the substance itself.▫ Examples

Breaking a piece of clay Stretching a rubber band Melting ice into liquid water Dry Ice sublimating into gas

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Chemical Properties and Chemical Changes

• Chemical properties of a substance are defined by the chemical changes it undergoes.

• Chemical changes transform the substance into a new identify.

• Chemical change or chemical reaction is the transformation of one or more atoms or molecules into one or more different molecules.

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Chemical Properties and Changes

• Chemical properties describe how substances can form new substances.

• A chemical property is any of a material’s properties that becomes evident during a chemical reaction.▫ Examples:

Combustibility (ability to burn) Easily oxidized (ability to rust) Toxicity (level of harm to organisms) Reactivity with other chemicals Types of chemical bonds that will form

• The change of one substance into another substance is called a chemical change.▫ Examples:

The burning of wood The rusting of iron Mixing baking soda and vinegar to produce carbon dioxide

gas

Physical and Chemical Changes

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Indicators of a

Chemical Change

• Color Change▫ Can be tricky to interpret▫ Some color changes are just a

mixture, not a chemical change Physical change – mixing food

coloring into water (mixture) Chemical change – iron

rusting due to oxygen (something new)

• Gas produced▫ Has to be a new substance, not

boiling!• Temperature change

▫ Gets hot – exothermic reaction▫ Gets cold – endothermic

reaction• Precipitate formed

▫ A solid is formed when reacting two or more fluids

• Odor change▫ A new smell!

• Light or sound production▫ Boom!

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Physical vs. Chemical

• Examples:

– melting point

– flammable

– density

– magnetic

– tarnishes in air

physical

chemical

physical

physical

chemical

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• Examples:

-rusting iron

-dissolving in water

-burning a log

-sublimation

-grinding spices

Chemical and Physical Change Practice Quiz #1

Chemical

Physical

Chemical

Physical

Physical

Practice Quiz #1; Practice Quiz #2

Physical vs. Chemical

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COMPLETE CHEMISTRY PACKET USING ONLINE

TEXTBOOK

Mr. Ganey’s Webpage Science Booknotes (Textbook) Chemistry Textbooks

Matter and Energy Textbook Chapter 2

Extension:

Make vocabulary flash

cards from Chapter 1

Study Guide (#1-18)

and Chapter 2 Study

Guide (#1-10)