Physical Changes vs. Chemical Changes

Physical Changes vs. Chemical Changes

Learning Objectives:

• We will investigate how evidence of chemical reactions indicate that new substances with different properties are formed.

• We will identify if a reaction is chemical or physical and explain how you decided.

Physical Changes

A substance is altered but it is not transformed into another substance. There is no change in composition, only a change in appearance.

Examples of Physical Changes

Breaking a glass bottle into tiny pieces.

Water evaporating from a puddle.

Chopping a pile of wood to use for a fire.

Physical Properties

• Characteristics that are observed or measured without changing the identity of a substance:

• Magnetism, Ductility, Malleability, Color, Texture, and Shape.

Chemical Changes

A change that results in the formation of new chemical substances.

A change in composition; new substances have different properties.

Most chemical changes cannot be reversed.

Examples of a Chemical Change

A piece of firewood burning

Baking soda reacting with vinegar

A piece of food becoming moldy

Chemical Properties

• Characteristics that can only be observed by changing the identity of a substance:

• Flammability, Ability to Rust, Ability to Tarnish, Ability to Rot/Spoil, Combustibility, and Toxicity.

Evidence of Chemical Reactions

• Unexpected change in energy (heat or light)

• Unexpected change in color

• Production of gas

• Production of precipitate

• Change in odor

Multiple Choice

Would dissolving sugar into a cup of coffee be considered a physical or chemical change?

• Physical Change

• Chemical Change

Multiple Select

Identify 3 physical changes that could occur with a sheet of paper.

• Burning it.

• Crumpling it.

• Ripping it.

• Eating it.

• Cutting it.

Open Ended

Identify 2 physical properties of a pencil.

Multiple Choice

Is the process of digestion a physical or chemical change?

• Physical Change

• Chemical Change

Multiple Choice

Identify the evidence of a chemical reaction for exploding fireworks.

• Flammability

• Combustibility

• Toxicity

Multiple Choice

Identify the evidence of a chemical reaction for burning sugar.

• Flammability

• Ability to Rot/Spoil

• Combustibility

Poll

Did you like this lesson?

• Yes

• No

Open Ended

What can I do to make this lesson better?

Open Ended

Do you have any questions on Physical Changes and Physical Properties?

Open Ended

Do you have any questions on Chemical Changes and Chemical Properties?

Don't forget to do your homework!

Miss Wadhams