The Science Fair is often one of the most anticipated events of the school year, especially in elementary school. Students can show off their love and knowledge of science, as well as their creativity. Choosing which project to do can often be a daunting task, but there are several that are simple enough for any grade level that are also fun and educational.

Kids love sweetness and lemonade and this simple experiment can help judge the sweetness of sugar substitutes and whether you need more or less water while using them. Mix up a few batches of lemonade using different sweeteners, including regular sugar, honey and artificial sweeteners. Measure the volume of water used in each and taste the lemonade. Have friends and family do the same and then tell you if any is more or less sweet than the batch with regular sugar. For the ones that are less sweet, adjust the amount of sweetener by adding more to learn how many tablespoons of sugar substitute it takes to equal one tablespoon of sugar. Write up your findings on poster board, where you will present them with the different lemonades at the fair.

This experiment results in a colorful rainbow of flowers. Start with six white carnations, each in its own individual cup of water with about half of the stem cut off. Add 20 to 25 drops of different food colorings to each cup. Over the course of several days, watch the white petals turn the color of the food coloring as the stems absorb the water and coloring together. You can also split the stem down the middle and put each half in a different cup with different colorings and watch the petals turn two shades rather than one. Record each step of the experiment, including how long each flower took to turn transform, as well as how much water and coloring was used.

This simple experiment can demonstrate how different shades of soda can tarnish pennies, the same way the American Dental Association has determined that soft drinks tarnish teeth. You will need several sodas of various shades, including Sprite, Mountain Dew, Dr. Pepper, Coke and Pepsi, as well as distilled water. Fill cups with each of the liquids and drop a penny in the cups, with the distilled water being the control cup. Each day observe how much the pennies have tarnished and write your findings in a journal to determine if the acidic nature of darker-colored sodas corrode pennies faster than lighter-colored ones.

Bowls, water and lemons are all you need for this experiment. Fill one bowl with water and drop a whole lemon inside. You will find that the lemon is buoyant and will float to the top. Take a second lemon and cut into four smaller pieces. When you drop it in water, the pieces will sink to the bottom as the lemon's pulp absorbs the water, causing it to weigh down. The whole lemon has its skin still in tact to protect its pulp from water absorption, which is why it will float.