Physical Changes in Matter

Questions and Answers

Which of the following best describes a physical change?

It cannot be reversed in any situation.

It alters one or more physical properties without changing the substance. (correct)

It creates new substances with distinct properties.

It only involves changes in chemical composition.

What happens to a substance during a chemical change?

It undergoes a process where no new substances are formed.

The substance maintains its original properties.

It can always be reversed to its original form.

New substances are created with different properties. (correct)

Which example illustrates a physical change?

Burning a candle.

Rusting of iron.

Melting ice into water. (correct)

Baking bread.

Why is the rusting of iron considered a chemical change?

<p>It forms a new substance called iron oxide.</p> Signup and view all the answers

Which process is an irreversible chemical change?

<p>Burning wood.</p> Signup and view all the answers

Study Notes

Physical Changes

Physical change alters physical properties without changing the substance's identity.
Characterized as reversible, allowing a return to the original state.
Substances remain the same despite changes in form.

Examples of Physical Changes

Melting Ice: Ice (H2O) transforms to liquid water, maintaining chemical identity.
Tearing Paper: Results in smaller paper pieces; composition of paper remains unchanged.
Dissolving Sugar: Sugar combines with water, remaining chemically sugar but in solution.

Experiments Demonstrating Physical Changes

Freeze and melt an ice cube to observe change and reversal.
Cut or fold paper to experience a physical change without altering its substance.
Stir sugar into water to witness its dissolution while retaining its identity.

Chemical Changes

A chemical change creates one or more new substances with distinct properties.
Typically irreversible, impeding a return to the original substance.
New substances formed possess different properties from the starting materials.

Examples of Chemical Changes

Burning Wood: Wood converts to ash and smoke, creating new chemical substances.
Rusting Iron: Iron reacts with oxygen and water to form iron oxide (rust).
Baking a Cake: Ingredients react during baking, yielding a new edible product.

Experiments Demonstrating Chemical Changes

Burn a small piece of paper (with adult supervision) to observe combustion and ash formation.
Leave a metal object outside to rust, illustrating long-term chemical change.
Mix vinegar and baking soda to create bubbles indicating a chemical reaction and new substance formation.

Description

Explore the concept of physical changes in matter through this quiz. Understand the characteristics and examples of physical changes, such as melting ice and tearing paper. Test your knowledge and see how well you recognize reversible changes without the formation of new substances.