Unit 1 Review: Chemical & Physical Changes

A chemical combination of two or more elements is called...

• a mixture.

• a compound.

• an atom.

Two substances are combined. Gas is released, and a tall, black column forms. This is an example of a

• physical property

• chemical property

• physical change

• chemical change

"Melting of ice" is an example of...

• a physical change.

• a chemical change.

Which is not an element?

• carbon, C

• oxygen, O₂

• helium, He

• salt, NaCl

Which indications of a chemical change occur when sodium is combined with water? (Check all that apply.)

• color change

• formation of a gas (bubbles)

• temperature change

• formation of a precipitate

When some properties change, but the identity of the substance remains the same, this is a...

• physical change.

• chemical change.

• nuclear change.

Which of the following are pure substances? (Check all that apply.)

• Carbon dioxide (CO₂)

• Milk

• Salt water

• Nitrogen (N₂)

Which of the following are examples of chemical changes? (Check all that apply.)

• Burning paper

• Cutting paper

• Iron rusting

• Wrinkling paper

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

How do you identify an element? (Check all that apply.)

• It is made of only one type of atoms.

• It is made of different type of atoms.

• It can be found on the Periodic Table.

• It is represented by a chemical symbol.

Gloria’s family built a wood fire in the fireplace. The next day, Gloria noticed that there was no wood left in the fireplace, only ashes. Which best explains this?

• Wood is separated from the ashes as it burns.

• Wood becomes a new substance as it burns.

• Ashes have the same properties as wood.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5