Understanding Phase Changes and Physical vs. Chemical Changes

What is a phase change?

• A change in the color of a substance

• A change in the temperature of a substance

• A change in the state of matter of a substance

• A change in the chemical composition of a substance

Which of the following is an example of a physical change?

• Burning wood

• Rusting iron

• Melting ice

• Digesting food

What distinguishes a chemical change from a physical change?

• A chemical change results in a new substance

• A chemical change is always reversible

• A chemical change involves a change in temperature only

• A chemical change involves a change in appearance only

What are the products formed when baking soda reacts with vinegar?

• Acetic acid and sodium bicarbonate

• Hydrogen and sodium chloride

• Sodium acetate and carbon dioxide

• Water and oxygen

Which of the following is NOT a sign of a chemical change?

• Emission of light

• Change in state

• Change in color

• Formation of bubbles

Which of the following is an example of a chemical change?

• Folding paper

• Boiling water

• Chopping wood

• Combining baking soda and vinegar

What is a key characteristic of a chemical change?

• It is always reversible

• It involves a change in state

• It is always temporary

• It results in a new substance

Why are phase changes considered physical changes?

• They are irreversible

• They only change the appearance of the substance

• They result in a new substance

• They involve a change in chemical composition

Which of the following is a reversible physical change?

• Cooking an egg

• Rusting iron

• Melting ice

• Burning paper

What happens to the identity of a substance during a physical change?

• It disappears

• It remains the same

• It becomes a new substance

• It changes completely