When was the last time you gave rocks and dirt any respect? In these experiments of earth science for kids, we are about to change all that. Kids will learn fascinating things about soil, rocks, and nature's cycles.
Needed: sand, a couple of rocks, magnifying glass, white sheet of paper
Challenge Question: What is sand made of?
Do It: Look through a magnifying glass at a few grains of sand. Do they look different up close? Does it all look the same? Where does sand come from? Draw or talk about your observations.
Find two rocks. Hold them over the white piece of paper and rub them together hard. What falls onto the paper? What would happen if you kept rubbing the rocks together? What might make rocks rub together naturally? What else is on the beach that could get ground into small pieces of sand?
Tip: Sand is made up primarily of rocks, minerals, and shells. When these are eroded by water or wind, we are left with tiny pieces called sand that settle to the bottom and are washed up on the shore.
Earth science for kids is a great way to create appreciation for common things they see in their world every day.
Needed: a little bit of soil, decaying leaf, fresh leaf, magnifying glass
Challenge Question: Where does soil come from?
Prep: Lay out in a line: the fresh leaf, the decaying leaf, the soil.
Do It: Point out the fresh leaf and the decaying, or rotten, leaf. How are the two leaves different? How are they similar? Look at them under the magnifying glass.
Now look at the decaying leaf and at the bits of soil close up and under the magnifying glass. How are they similar? How are they different?
What happened to the fresh leaf to make it brown and ragged? What do you think will happen to the decaying leaf next?
Do you see other things in the soil, too?
Tip: Your role in this experiment is to help kids independently see the leaf's progression from new leaf → decaying leaf → soil. Discoveries like these are what makes earth science for kids so exciting! Don't give it away; kids need time to make the connections on their own, but you can provide occasional clues. Follow up with Soil Cycle, Part 2.
Needed: a little bit of soil, decaying leaf, fresh leaf, magnifying glass, possibly access to the plant where the leaf came from
Challenge Question: How does soil feed plants?
Guided Exploration: Do plants and leaves need vitamins? (Yes.) Where do you think they get their vitamins? (Their vitamins mostly come from the soil.) How do the vitamins get from the soil into the plants? (Through the roots.)
(Hold up the green leaf.) Are there vitamins in this leaf? (Yes. Hold up the decaying leaf.) Are there vitamins in this leaf? (Yes--it's old, but the vitamins are still there.) Are there vitamins still there when the leaf turns into soil? (Yes--they have just broken down into small pieces.)
Why is it important that the soil has vitamins in it? (So the plants can use the vitamins to grow.) If the plants are sucking up all the soil's vitamins, does it take vitamins away from the soil? (Yes.) Any ideas how it gets those vitamins back? Will there be more dead leaves dropping onto the soil? Do those leaves have vitamins?
Tip: This is more of a guided exploration than an experiment, but it is an important concept of earth science for kids. When kids see how it all goes in a circle, over and over, a light bulb goes off in their heads. Nature feeds itself. It's miraculous!
Needed: an area that has some rocks, magnifying glass (optional)
Challenge Question: Is every rock different?
Do It: Go outside and search for interesting rocks. Let kids collect some favorites to keep for themselves. Wash them off when you get home; the water will bring out colors they didn't even know were there.
Examine the rocks. Which do they like the best? Why? Sort them by color or size. What do their rocks remind them of? What is special about their rocks?
Have a child look closely at one particular rock. Have him close his eyes while you mix up the rocks. When he opens his eyes, can he find his rock?
Tip: Try to find several different kinds of rocks. They come in all shapes, sizes, and colors, though rocks from a certain area may look very similar. You can also buy rocks and collections that have a nice selection of colorful rocks and minerals.
Needed: an assortment of different kinds of rocks, vinegar, eyedropper
Challenge Question: Which rocks have calcite in them?
Prep and Explanation: Set out a small cup of vinegar and the eyedropper. Explain that some rocks have a mineral called calcite in them. When vinegar or another acid touches calcite, it fizzes. We are going to test some rocks to see which ones have calcite in them.
Do It: Demonstrate how to use the eyedropper. Kids may need some practice at this. Show them how to put just a few drops on each rock, then watch to see what happens. If it fizzes up, it has calcite in it!
Tip: Limestone is a common form of calcite. So is chalk. Because calcite is so common, it is usually possible to find many rocks that have this mineral, especially those that seem to be a conglomeration of many rocks. Smooth rocks, such as river stones, may be less likely to contain calcite.