A simple experiment can show you how heat is related to the evaporation of water. First, find at least two cardboard boxes, as well as at least two light bulbs with different wattages. In the bottom of each box, put a container filled with the same amount of water. In the top of each box, cut a hole for a light socket to go. Tape a different light socket in place in the top of each box so the light will shine into the box and onto the pan of water. Put a different watt light bulb in each of the sockets, shining down on the water. The water in the box with the light bulb that has a higher wattage should evaporate more quickly. You can observe this by recording the amount of evaporation over time under the different bulbs.
The imploding-can experiment shows how gases respond to heat. Empty a soda can and fill it with a tbsp. of water. Heat the can, while holding it with tongs, until the water inside is boiling. Remove the can from the boiling water and quickly insert the can upside down into a large pot filled with ice water. The hot air in the can will rush out suddenly and the can will implode.
You can also use an experiment to show how colors affect how heat is absorbed. You will need two identical glasses of water, two rubber bands, a thermometer, white paper and black paper. Fill the glasses with the same amount of water and wrap each with one of the papers, using the rubber band to hold the paper on the glass. Leave both glasses in the sun for two hours and measure the temperature of each. The black glass will be hotter, as the color black absorbs more heat, while white reflects more.
This experiment shows how surface area affects evaporation. Fill a plate and a glass with the same amount of water. Leave both in the sun for at least two hours. The heat from the sun will cause more evaporation in the plate than in the glass, because there's more surface area for evaporation to occur in.