Changes Around Us

What is a physical change?

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

• A change in the taste of matter

• A change in the color of matter

• A change in the smell of matter

Give an example of a physical change.

• Rusting of iron

• Boiling of water

• Burning of wood

• Melting of ice

What is a chemical change?

• A process in which substances change color

• A process in which substances are converted into energy

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

• A process in which substances remain the same

Provide an example of a chemical change.

• Burning of wood

• Mixing salt and water

• Melting ice

• Cutting paper

What is a reversible change?

• A change that can be undone or reversed

• A change that can only happen once

• A change that has no impact

• A change that is irreversible

Give an example of a reversible change.

• Burning wood

• Boiling water

• Rusting metal

• Melting ice

What is an irreversible change?

• A change that can be easily reversed

• A change that is temporary

• A change that cannot be undone or reversed

• A change that has no impact

Provide an example of an irreversible change.

• Mixing of salt and water

• Burning of paper

• Freezing of water

• Melting of ice

How can you identify a physical change?

• By observing changes in the state, shape, or form of a substance without altering its chemical composition.

• By changing the color of the substance

• By altering the chemical composition of the substance

• By observing changes in the smell of the substance

How can you identify a chemical change?

• By smelling a different odor

• By observing the change in temperature

• By observing the formation of a new substance, change in color, production of gas, or release of energy.

• By tasting the substance