Classification, Properties, Changes, Conservation Unit Test Rev.

A student mixes yellow powder with water. Which observation would prove a CHEMICAL change occurred?

• The powder DISSOLVED in the water

• The water turned the COLOR yellow

• The bag's TEMPERATURE changed

• The STATE OF MATTER changed

Which of the following options provides evidence of a CHEMICAL change?

• Wood is burned releasing ash and smoke

• Rocks separate when soil is sifted

• Water turns to ice when you put it in the freezer

• Salt dissolves in water

Which of the following examples provides evidence of a PHYSICAL change?

• Wood is burned and releases ash and smoke

• Iron rusts over time

• When mixed, baking soda and vinegar form gas bubbles

• A piece of paper changes shape when you rip it up

A white tablet is dropped into water. The water becomes cloudy and bubbles are produced. What type of change has occurred?

• Physical change

• Chemical change

• No change

Which observations prove a chemical change has occurred?

• Dissolving and expected color change

• Mixing and dissolving

• State of matter change and boiling water bubbles

• Unexpected color change and temperature change

When mixing milk and vinegar, a white, chunky, solid substance is formed. What has occurred?

• Physical change: state of matter

• Chemical change: production of a solid

• Physical change: freezing

• Chemical change: rust

When iron is exposed to air over a long period of time, it forms rust. This is an example of what?

• A new substance forming

• Color change: no new substance

• Shape change: no new substance

• Burning: a new substance

A physical change...

• Changes the physical properties of an object, but does not create a new substance.

• Creates a new substance and cannot be undone.

A chemical change...

• Changes the physical properties of an object, but does not create a new substance.

• Creates a new substance and cannot be undone.

Is this an example of a physical or chemical change?

• Physical

• Chemical