Place 1 cup of water into three different cups. Into one cup, add ¼ cup sugar, stirring until it is dissolved. Into the second cup, add ¼ cup salt, stirring until dissolved.
Heat the remaining 3 cups of water until hot.
Place 1 cup of hot water into three different cups. Into one cup, add ¼ cup sugar, stirring until it is dissolved. Into the second cup, add ¼ cup salt, stirring until dissolved.
Place one candy heart into each cup of water. Set a timer for 2 minutes.
When the timer goes off, check the candy hearts and make note of which have changed.
Continue checking the candy hearts every 2 to 5 minutes, making note of the changes.
Discuss which liquids caused the candy canes to dissolve faster/slower and why. If desired, repeat the experiment using different room-temperature liquids such as vinegar, liquid dish soap, oil, soda pop, etc.