Taking the kids on a field trip to identify bird songs is a good science activity to help them learn about nature. Bring along a pair of binoculars, a bird guide and maybe a snack, and head to a local state park or even your own backyard, if you have one. Scan the trees for birds and listen for their calls. Isolate one that sounds interesting to you and try to put it to words. For example, many bird guides describe the American Robin's call as "Cheerily cheer up, cheerio." Try to find the call in the guide, or identify the bird by sight and try to match it up to its call.
You can conduct an experiment that allows your kids to watch crystals grow under a microscope by using a vial of salicylic acid solution, a thin pipette, a colored plate and a microscope slide. Instruct your students to set the slide on the colored plate, and then shake the vial while tightly capped for 20 seconds. They can then use the pipette to drop a small drop of the solution onto the slide, where it should dry quickly. Have the kids watch the solution through the microscope; the crystals will form as the solution dries.
Help kids understand just how big the planets are in relation to one another with food. The Easy Fun School website recommends getting two peppercorns for Mercury and Mars, two peas for Venus and Earth, two plums for Uranus and Neptune, a grapefruit for Jupiter and a large orange for Saturn. Put them on a table in order, with the closest to the sun all the way on the left and the farthest all the way on the right. The order is: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. Talk to your students about how different the sizes are, and ask them how many of one of the smaller planets -- e.g., Mercury -- could fit inside Jupiter, for example.
This activity will help kids understand how acids work in nature. Get a clear glass, a piece of sidewalk or blackboard chalk and either white vinegar or cider vinegar. Vinegar is a weak acid often used in cleaning solutions and in cooking. Pour the vinegar in the glass until it is half full. Drop the piece of chalk into the vinegar. Have the kids record what happens in their own personal science journals. The chalk should produce bubbles after coming in contact with the vinegar due to carbon dioxide being released.