• Science fair topics for 10th graders need to involve mature concepts.science image by peter Hires Images from Fotolia.com
  
  Science fair topics for 10th graders can usually cover any scientific field as long as the project is mature enough for a high school student. School science fairs tend to follow a strict set of guidelines that require a question, a hypothesis to answer the question, an experiment to prove or disprove the hypothesis and a conclusion.
  
  

Acidity and Cleaning

• Explore the concept of acidity for a 10th grade science project that demonstrates the acid levels and effects of different liquids. The project can include hypotheses on the acidity of assorted liquids and how well each liquid will clean dirt from a penny. Liquid samples can include any basic fluid, such as water, lemon juice, lime juice, orange juice, tomato juice and vinegar.
  
  Preparation for the experiment consists of creating a dirty penny for each liquid sample. For scientific accuracy, each clean penny needs the exact same kind of dirt covering so that each liquid sample is trying to clean the exact same type and amount of dirt. The sticky muck often seen on pennies is replicated by dipping each one in a thick mixture of dirt, sand, apple juice, maple syrup and a little vegetable oil.
  
  Once the muck-covered pennies dry, you can start the experiment. The experiment includes testing each liquid with a pH strip to discover its acidity level. After testing, a penny soaks in each container of liquid for a predetermined amount of time. The last step of the experiment includes removing and wiping the pennies dry to discover which liquid sample did the best cleaning job.
  
  

Cleaning Oil Spills

• For a science fair project with an environmental focus, students can investigate the best way to clean up after an ocean oil spill. The general project consists of different oil spill cleaning methods or products and a hypothesis about how well each one will work.
  
  The experiment consists of individual containers of salty "ocean" water contaminated with any type of crude oil. You can include unconventional and conventional oil spill cleaning methods for a well-rounded experiment. Odd cleaning selections can include baking soda, a paper towel, a piece of felt, a wire skimmer, shampoo and so on.
  
  

Plant Crowding

• For a biology-focused science project, study the effects of overcrowding on plants. The project question can include a study on how crowding affects one specific type of plant, or it can be a study of the overall effects of crowding on several different types of plants.
  
  A hypothesis about how a plant or plants will react to crowding can include separate sections on what reactions will be after one week, two weeks and so on. The experiment consists of four plant pots--one with one plant, one with two plants, one with four plants and one with eight plants. The project includes charting each plant on a weekly basis to measure growth and health.