chemical and physical changes
Which of the following is an example of a chemical change?
Melting ice
Burning wood
Boiling water
Breaking glass
Burning wood
Which of the following is an example of a reversible physical change?
Melting ice
Burning wood
Rusting iron
Cooking an egg
Melting ice
What happens to the molecules during a chemical change?
They rearrange to form new substances.
They move faster but remain the same.
They change state but retain their identity.
They expand and contract without changing.
molecules rearrange to form new substances.
Why is dissolving sugar in water considered a physical change?
Because it forms a new substance.
Because the sugar molecules break apart chemically.
Because the sugar retains its chemical identity.
Because it releases energy in the form of heat.
because the sugar retains its chemical identity.