Changes Around Us

What is a physical change?

• A physical change is a change in the population of a city

• A physical change is a change in the form or state of matter without any change in its chemical composition.

• A physical change is a change in the weather

• A physical change is a change in the speed of light

Give an example of a chemical change.

• Rusting of iron

• Melting of ice

• Evaporation

What is a chemical change?

• A process in which one or more substances are converted into different substances with different properties

• A process that only involves physical changes

• A process in which substances remain the same

• A process that does not involve any substances

Give an example of a chemical change.

• Cutting paper

• Mixing salt and water

• Boiling water

• Burning of wood

What is a reversible change?

• A change that can only happen once

• A change that is irreversible

• A change that can be undone or reversed

• A change that has no impact

Provide an example of a reversible change.

• Rusting of iron

• Melting ice

• Cooking an egg

• Burning wood

What is an irreversible change?

• A change that cannot be undone or reversed

• A change that can be easily reversed

• A change that is temporary

• A change that has no impact

Provide an example of an irreversible change.

• Mixing salt and water

• Melting ice

• Burning of paper

• Folding a piece of paper

What are chemical reactions?

• Biological processes in living organisms

• Processes that result in the transformation of one set of chemical substances to another

• Processes that result in the transformation of physical substances

• Changes in the weather

Explain the difference between physical and chemical changes.

• Physical changes involve a change in appearance or state, but the substance remains the same. Chemical changes result in the formation of new substances with different properties.

• Physical changes involve a change in state, but the substance becomes a different material.

• Chemical changes involve a change in appearance, but the substance remains the same.

• Physical changes result in the formation of new substances with different properties.