For this activity, you will need:

• A metal tray, pot-lid or cookie sheet
• Water
• A spray bottle or eyedropper
• A cold place (such as a refrigerator or freezer)

To start, fill the metal tray or cookie sheet with a thin layer of water and place it in a cold place, such as a refrigerator or freezer. As the water gets colder, the vapor in it will start to condense and form ice crystals on the surface of the tray or sheet. These ice crystals are similar to frost and hoarfrost, which form when the temperature is below freezing and the air is dry.

You can observe the ice crystals as they form and see how they change over time. You can also use a spray bottle or eyedropper to add water to the tray or sheet and see how the ice crystals grow and change.

This activity is a fun and easy way to explore the science of ice crystals and see how they form in different conditions. It’s also a great way to learn about the properties of solids and liquids!