Chemical and Physical changes

When heat is added to an ice cube, it will change to a

• liquid

• solid

• plasma

Tags

NGSS.MS-PS1-4

Burning a piece of paper is an example of a

• Physical Change

• Chemical change

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

An example of a liquid changing to a gas is

• Wood burning

• Paper tearing

• A pot of boiling water

• A lake freezing in the winter

Tags

NGSS.MS-PS1-4

Scrambling eggs is an example of

• A physical change

• A chemical change

• Solution

Tearing paper into small pieces is an example of a

• Mixture

• Physical change

• Chemical change

Rust will most likely occur when it is

• wet

• greasy

• dry

Tags

NGSS.MS-PS1-2

Glass bottle that is shattered

• Chemical Change
• Physical Change

Which lab experiments below describe a situation where a chemical change has occurred? Check all that apply.

• After adding zinc (Zn) to hydrochloric acid (HCl), a student observes bubbles forming in the solution and a thermometer registers a  $10\degree$  change in temperature.

• A student uses a mortar and pestle (a grinding stone) to break up large pieces of ammonium thiocyanate ( $NH_4SCN$  ) into smaller pieces.

• After combining Unknown A (a solid, white crystal) with Unknown B (a clear, odorless liquid), there is a strong smell produced and a thermometer registers a  $15\degree$  change in temperature.

• A student dissolves sugar ( $C_6H_6O_6$  ) into water ( $H_2O$  ). The sugar crystals seem to disappear.

What key words, when present in a question about chemical reactions, might indicate a chemical change is occuring? Check all that apply.

• Bubbling

• Fizzing

• Dissolving

• Evaporating

A student combines two clear, colorless solutions shown here. When combined, the temperature changed from  $25\degree$  to  $23\degree$  and a white substance rapidly formed and settled at the bottom of the container. What most likely happened to produce these results?

• One of the original compounds came out of solution

• The solutions reacted chemically

• Some of the water froze into ice crystals

• Rapid evaporation of water occured, leaving a solid