PHYSICAL AND CHEMICAL CHANGE

Which of the following is a physical change?

• Burning wood

• Rusting of iron

• Melting of ice

• Baking a cake

What characteristic is common to both physical and chemical changes?

• Both involve the formation of new substances

• Both can often be easily reversed

• Both involve a change in the physical state of matter

• Both involve a change in the properties of matter

When a chemical change occurs, which of the following is true?

• The substance can be easily returned to its original state

• Only the physical appearance of the substance changes

• New substances with different properties are formed

• The chemical composition remains the same

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

• Dissolving sugar in water

• Freezing water to form ice

• Breaking a piece of chalk

• Cooking an egg

Which of the following best describes the process of sublimation?

• Solid to liquid

• Liquid to gas

• Solid to gas

• Gas to liquid

During a physical change, which of the following statements is accurate?

• The identity of the substance changes

• The process is often irreversible

• The chemical structure of the substance changes

• The substance retains its original composition

Why is rusting of iron considered a chemical change?

• It only changes the color of the iron

• It can be reversed by polishing the iron

• It forms a new substance with different properties

• It only changes the physical shape of the iron

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

• Formation of a gas

• Change in temperature

• Change in state from solid to liquid

• Change in color

Which of the following is an irreversible physical change?

• Boiling water

• Cutting a piece of paper

• Melting wax

• Stretching a rubber band

When vinegar reacts with baking soda, which of the following observations indicates a chemical change?

• The mixture becomes cold

• The solution remains clear

• Bubbles of gas are produced

• The baking soda dissolves