Physical and Chemical Changes

What is the definition of a physical change?

• 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 color of matter without any change in its chemical composition.

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

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

Give two examples of chemical changes.

• Boiling water

• 1. Rusting of iron 2. Burning of wood

• Freezing water

• Mixing salt and sugar

What are the evidences of a chemical change?

• Change in volume

• Change in texture

• Formation of a precipitate, change in color, release of gas, and absorption or release of heat

• Change in state of matter

List two properties of physical changes.

• Physical changes always result in a change in color.

• Physical changes only occur in solids.

• Physical changes always involve a change in temperature.

• 1. Physical changes do not change the chemical composition of a substance. 2. Physical changes are usually reversible.

Differentiate between physical and chemical changes.

• Physical changes involve a change in form or appearance without a change in chemical composition, while chemical changes involve a change in chemical composition resulting in the formation of a new substance.

• Physical changes result in the formation of a new substance, while chemical changes involve a change in form or appearance without a change in chemical composition.

• Physical changes involve a change in chemical composition, while chemical changes involve a change in form or appearance without a change in chemical composition.

• Physical changes involve a change in form or appearance and chemical composition, while chemical changes involve a change in form or appearance without a change in chemical composition.

Explain the process of crystallization.

• Crystallization is the process of forming solid crystals from a homogeneous solution by cooling or evaporation of the solvent.

• Crystallization is the process of forming solid crystals from a heterogeneous solution by heating the solvent

• Crystallization is the process of forming gas crystals from a homogeneous solution

• Crystallization is the process of forming liquid crystals from a heterogeneous solution

Describe the process of rusting.

• Rusting is the process of iron or steel reacting with oxygen and water to form iron oxide, also known as rust.

• Rusting is the process of copper reacting with oxygen and water to form copper oxide.

• Rusting is the process of iron or steel reacting with carbon dioxide and water to form iron oxide.

• Rusting is the process of aluminum reacting with oxygen and water to form aluminum oxide.

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 observing changes in the color of a substance

• By observing changes in the taste of a substance

• By observing changes in the smell of a substance

Provide an example of a chemical change.

• Burning of wood

• Mixing salt and water

• Melting ice

• Cutting paper

What are the signs of a chemical change?

• Change in texture

• Change in temperature

• Change in state

• Formation of a precipitate, change in color, release of gas, and absorption or release of energy.