Amazing Changes: End of unit review

A reversible change is:

• a change that cannot be undone

• a change that can be undone

• a permanent change

• a temporary change

An irreversible change is:

• a change that can be undone

• a change that cannot be undone

• a temporary change

• a reversible change

Class 6 set up this test to find out what happens when bicarbonate of soda is mixed with vinegar. What is the expected outcome of this experiment?

• A gas is released, causing bubbling and fizzing.

• The mixture turns blue.

• The mixture becomes solid.

• Nothing happens.

Here is the rust triangle. Name one thing that you could take away that would prevent rust from developing.

• Oxygen

• Tin

• Fire

• Soil

Is iron the only material that rusts?

• No, other materials can rust as well.

• Only metals rust, and iron is one of them.

• Rusting is a process unique to iron.

• Yes, iron is technically the only material that can rust.

How can you answer the question, 'Is iron the only material that rusts?'?

Select all the options.

• By testing each material for rusting

• By observing the color change in materials

• By checking the weight change in materials

• By exposing materials to water and air

Question 6: Here is the burning triangle. Name one thing that you could take away that would prevent burning.

• Oxygen

• Fuel

• Heat

• All of the above

Which fabric is the most dangerous when it catches fire?

• None of the above

• Cotton

• Wool

• Nylon

Are these reversible or irreversible changes?

Groups:

(a) Reverisble

,

(b) Irreversible

• Rusting

• Freezing

• Evaporation

• Making elephant's toothpaste.

• Burning

• Mixing sand and salt

What new substance was created when they mixed baking soda and vinegar?