Chemical and Physical Changes

• What are examples of physical changes?

  Melting butter and cracking eggs
• What occurs during a physical change?

  A substance changes state or shape or breaks into pieces without forming new substances
• Can many physical changes be reversed?

  Yes, many physical changes can be reversed
• What is an example of a reversible physical change?

  • Freezing juice to make an ice lolly
• What is another example of a reversible physical change?

  • Mixing sand with water
• What is an example of a reversible physical change involving a solute?

  • Dissolving sugar in water
• What defines a chemical change?

  A chemical change produces one or more new substances
• What is an example of a chemical change in cooking?

  Cooking eggs, cakes, or other food
• What is an example of a chemical change involving metals?

  Steel rusting
• What happens when an acid reacts with an alkali?

  It produces a salt and water
• What happens to the particles of a substance when it changes state?

  The particles stay the same, but their arrangement and movement change.
• How do the particles in an ice cube behave when it melts into liquid water?

  The particles begin to move around each other instead of being in fixed positions.
• What is the arrangement of particles in liquid water compared to ice?

  The arrangement of particles in liquid water becomes random instead of regular.
• What occurs to particles during a chemical change?

  Particles break up and then join together in different ways.
• Why are new substances formed during a chemical change?

  Because particles break up and join together in different ways.