ET -- Physical and Chemical Changes

Is this a physical or chemical change?

• Physical

• Chemical

Which of the following observations would indicate a chemical change has happened? Select ALL correct answers.

• a solid precipitate forms

• heat energy is released

• breaks into smaller pieces

• folded in half

• a gas is produced

In this example, what is the evidence a chemical change has occurred?

• volume is increased

• no energy is released

• gas is being released

• a precipitate has formed

Bubbles form when water boils. Is this evidence of chemical change?

• Yes, because water is changing.

• Yes, because the water is reacting.

• No, because the vapor is still water.

• No, because water doesn't react with anything.

Every chemical change involves __________.

• dissolving substances

• the release of light and heat

• an increase in density

• the formation of a new substance

This is an example of _____ change.

• Physical

• Chemical

Wood is chopped into small pieces. Then, it is burned to cook food. This is an example of a ____ change followed by a ____ change.

• chemical, physical

• physical, chemical

• physical, physical

• chemical, chemical

Which type of change is occurring in the picture?

• Chemical

• Physical

True/False --- As this water boils, the release of a gas means a chemical change has occurred.

• True

• False

What type of change has occurred?

• Chemical

• Physical