Irreversible Changes

Question 1

Which of the following groups contains three everyday changes that each produce a new material and cannot be changed back to the originals?

Accepted Answer

Burning a candle, rusting a garden gate, mixing lemon juice with baking soda

Answer

Melting ice cubes, rusting a bike chain, stirring sugar into water

Answer

Dissolving salt in water, melting wax, burning a scrap of paper

Answer

Freezing juice, cooking an egg, rusting a metal nail

Question 2

Which of the following statements accurately defines an irreversible change and gives an example that fits that definition?

Accepted Answer

An irreversible change creates a new substance that cannot be turned back into the original; for example, burning a piece of paper so it becomes ash.

Answer

An irreversible change is a change that looks different but can be returned to the original form; for example, melting ice into water.

Answer

An irreversible change is only about a temperature increase; for example, heating a metal rod until it feels hot.

Answer

An irreversible change happens when something changes shape without forming a new material; for example, folding a sheet of paper.

Question 3

Which of the following statements best describes an irreversible change?

Accepted Answer

It is a change that forms a new substance that cannot be changed back into the original materials.

Answer

It is a change that only changes the shape of a material, which can later be reshaped to its original form.

Answer

It is a change that only makes a material hotter or colder, but the material itself stays the same.

Answer

It is a change that can be undone simply by cooling the material back down.

Try three questions