Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button if available to get a clue. Note that you will lose points if you ask for hints or clues!
cannot changes Chemical chemical chemical change chemical changes chemical reaction colour cooled down energy change frozen Frozen gas gaseous Gaseous hotter ice irreversible liquid melted new no new substance observations original physical reversible solid steam three toasted two