Name one Name one physicalphysical property property of this of this bear.bear.

Chemical PropertiesTheThe ability ability of a substance to undergo of a substance to undergo

chemical reactions and form NEW chemical reactions and form NEW substances substances

Chemical Properties Chemical Properties describedescribe CHEMICAL CHEMICAL CHANGESCHANGES

Example: burning a tree creates new substances (ash and smoke)

Examples of Chemical Properties

• Combustibility

• Reactivity with oxygen, acid or water

• Flammability

Give an Give an example of a example of a

chemical chemical property.property.

Study Buddy Review!!

Classify each as a physical or chemical property of matter:

• Blue Color• Ability to Rust• Density• Flammability• Reacts with a base to form water• Boiling Point• Reacts with water to form a gas• Luster• Mass• Odor

Physical Change is a change that affects one or more physical properties of

a substance.

What could you What could you do to this do to this lemon to lemon to change it change it

physically?physically?

How can you physically change the paper?

• Crumble Crumble it.it.

• Rip it.Rip it.

• Cut it.Cut it.

How can you physically change ice?

•Cut it.Cut it.•Melt it.Melt it.

Examples of Physical Changes

• Freezing water into ice cubes

• Sanding a piece of wood

• Cutting your hair

• Crushing an aluminum can

• Bending a paperclip

• Ironing your clothes

A chemical change occurs when a substance changes into something new. This occurs due to heating, chemical reaction, etc.

You can tell a chemical change has occurred if the density, melting point or freezing point of the original substance changes.

Examples of Chemical Changes…

• Combustion

• Electrolysis

• Oxidation

• Tarnishing

• Reacting with oxygen, acid or water

Evidence for Chemical Reactions…

• Color Change• Precipitation• Gas production• Temperature changes• Changes in properties

• Reaction with acids• Reaction with bases

(alkalis)• Reaction with oxygen

(combustion)• Ability to act as

oxidizing agent

• Ability to act as reducing agent

• Reaction with other elements

• Decomposition into simpler substances

• Corrosion

Discover Activity

• Obtain a small piece of chalk. Observe it and record its properties in your notebook.

• Place the chalk on a piece of paper and crush it with the back of a spoon. Record the changes that occurred in your notebook

Discover Activity (Cont.)

• Place some of the crushed chalk into the bowl of the spoon. Add about 8 drops of vinegar. Record what happens in your notebook.

Explanation

• Chalk is mostly a single substance, calcium carbonate. Do you think a new substance was formed when the chalk was crushed?

• Do you think a new substance was formed when vinegar was added? Provide evidence for your answers.

Physical Changes

• Changes that alter the form or appearance of matter.

• Does not change the substances in the matter into new substances.

Examples of Physical Changes…

• Changes in State– When matter changes from a solid to a liquid

or a liquid to a gas.– Ice/water vapor/liquid water

• Dissolving

• Bending, crushing, breaking, chopping

Check for understanding

Why is the melting of an ice cube called a physical change?

– The substance is still water, just the form has changed.

Chemical Change

• Occurs when a substance is transformed into a different substance.

• The newly formed substances have different properties than the original substances.

Discover Activity

• Take a beaker and fill with 50 mL of water

• Drop 3 drops of red dye into the water

• Make observations.

• Is it a physical or chemical change?

• Which one is the Solvent? Solute?

Cont. Discover Activity

• Now, add 5 drops of bleach to the solution of red colored water.

• Make observations.

• Is this a physical or chemical change? Explain.

Let’s See What You Have Learned Let’s See What You Have Learned About the Properties of Matter…About the Properties of Matter…