Changes of State

Physical changes to matter can be reversed because a new type of matter has not been created. Which TWO processes can be reversed and are therefore physical changes?

• cooking pasta

• baking a cake

• melting an ice cube

• boiling some water

• popping some popcorn

A teacher pours 100 milliliters of water into a glass bottle and stretches a balloon over the top.
The teacher slowly heats the bottle by placing it in a small container of boiling water until some of the water in the bottle changes to a gas. Which finding can the teacher use to prove there is gas in the bottle after it is heated?

• The balloon on top of the glass bottle is larger.

• Small droplets of water appear on the sides of the glass bottle.

• The glass bottle feels hot to the touch.

• There is more liquid water in the glass bottle.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-4

A teacher places two sheets of paper of the same size on a table. The teacher puts Paper A in a freezer for 10 minutes and burns Paper B. The table shows before and after information.

Which statements explain the change that happens to each sheet of paper?

• Paper A is no longer paper when it becomes cold in the freezer. Paper B cannot be formed back into paper once it is ash.

• Paper A can be cooled and still be paper. Paper B cannot change back to paper after being burned.

• Paper A will stay cold when it is removed from the freezer. Paper B will change back to a sheet of paper when cooled.

• Paper A can be cooled or warmed and still be paper. Paper B will always be paper even when it changes to ash.

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which is the best examples of a change that cannot be reversed?

• heating a wax crayon

• placing toys in a box

• cooling woup with an ice cube

• burning a piece of paper

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which two changes can be reversed?

• boiling an egg

• burning a piece of paper

• baking a cupcake

• freezing a bowl of water

• melting a wax crayon

Tags

NGSS.MS-PS1-4

Which of the following activities best demonstrates a change that can be reversed by heating or cooling?

• burning a piece of paper

• freezing water into ice cubes

• baking cookies in the oven

• cutting a piece of fruit

Tags

NGSS.MS-PS1-4

A student places four objects in an oven and records the changes in a table.

Which object can be changed back to its original form after cooling?

• bread dough

• chocolate bar

• potato pieces

• soft clay