An example of a biology project that is simple to complete either at home or in the science classroom involves growing two same-species plant seeds in wet and dry conditions. Use this experiment to demonstrate that seeds need moisture to germinate. Pour a teaspoon of cress seeds onto the center of two identical paper towels and spread tap water onto one of the towels --- this leaves you with a dry and wet condition for your seeds. Wrap the paper towels so you have covered over the seeds and position them where they will receive plenty of natural light. Return to observe the growth in your seeds at least once every other day, providing the wet condition towel with water when necessary. Take plenty of photographs of your experiment, which you can show on your science fair display before ending your experiment after at least two weeks.
Complete this example of a chemistry project with the assistance of your teacher or a parent as it requires you to handle boiling liquids. Grate a whole red cabbage into a mixing bowl and submerge the shredded leaves in boiling water. Let the mixing bowl cool off. When it is cool, the water will have turned a purple color. Carefully pour the purple liquid into a fresh mixing bowl through a strainer before discarding the shredded cabbage leaves. Set up a rack with eight test tubes and add four to five drops of your cabbage solution to each tube using a medicine dropper. Take a pH chart and test different substances, such as lime juice, vinegar, water, bicarbonate of soda and bleach. If the liquid turns a deeper purple or red, there is acid in the substance. If the liquid turns blue, green or yellow, the substance you have added is alkaline. Your cabbage solution acts as pH indicator, much the same as litmus paper.
This example of a physics experiment for your science fair project investigates the strength of magnets at different temperatures. To test the magnets at different temperatures, fill a shallow dish with 50 ball bearings -- use the same dish and same ball bearings for each temperature of magnet. Prepare identical magnets at different temperatures by placing individual magnets in: a freezer, a refrigerator, room-temperature environment, water heated to 120 Fahrenheit and boiling water. Always wear thick rubber gloves when handling magnets, as the extremes of temperature can be painful on your hands. To test a magnet, lay it flat in the center of the dish of ball bearings for 10 seconds before lifting it out, placing it in a plastic container, shaking loose the ball bearings and counting them. The more ball bearings the magnet attracted, the higher its magnetism. Compare the performance of the magnets at each temperature.
Demonstrate the greenhouse effect during this simple environmental science project. Place two identical shoeboxes beside each other in direct sunlight, such as on a table outside, and fill each one with two inches of potting soil. Place a thermometer in the middle of the soil so you can read its display clearly when standing above the box. Wrap over the top of one of the boxes with transparent plastic wrap so that it is airtight. Start a timing device and write down the temperature in each of the boxes every five minutes. Finish the experiment after at least 1/2 hour. Then draw a line graph of your results with time on the horizontal axis and temperature on the vertical. You should note that the temperature rises faster and reaches a higher overall level in the box you wrapped in plastic as this box replicates a greenhouse condition.