Why does sand settle to the bottom of the ocean, but salt mixes in? How do people get sea salt out of the sea?
Could you tell the difference between sugar and salt without tasting them? Have you ever seen a crystal up close? How are crystals made?
Do liquids all freeze at the same temperature?
What are the differences between ice, water, and steam? What are the similarities between water, juice, and milk?
What is a force? Do we have force? Do solids have force? What about liquids and gases?