8th Grade Science Fair Project Ideas

Science classroom with teacher at chalkboard

ThoughtCo / Lara Antal

8th grade science fair projects tend to involve the scientific method and designing an experiment and not making models or explaining processes. You'll be expected to present data in the form of tables and graphs. Typed reports and posters are the norm (sorry, no handwritten text). You should do the project yourself, rather than enlist heavy-duty help from a parent or older student. It's appropriate to cite references for any information that isn't common knowledge or that draws on the work of others.

Ideas for Chemistry Projects

  • Does air temperature affect how long soap bubbles last? Does relative humidity?
  • What ratio of vinegar to baking soda produces the best chemical volcano eruption?
  • What type of plastic wrap prevents evaporation the best?
  • What plastic wrap prevents oxidation the best?
  • Can a saturated solution of sodium chloride still dissolve Epsom salts?
  • If you shake up different kinds or brands of soft drinks (e.g., carbonated), will they all spew the same amount?
  • Do all dishwashing detergents produce the same amount of bubbles? Clean the same number of dishes?
  • How permanent are permanent markers? What solvents (e.g., water, alcohol, vinegar, detergent solution) will remove the ink? Do different brands/types of markers produce the same results?
  • Is laundry detergent as effective if you use less than the recommended amount? More?
  • Do all hairsprays hold equally well? Equally long? Does type of hair affect the results?
  • What effect do additives have on the crystals? You could add food coloring, flavorings, or other 'impurities'.
  • What steps can you take to maximize crystal size? You can affect vibration, humidity, temperature, rate of evaporation, purity of your growth medium, and time allowed for crystal growth.
  • How does the pH of soil relate to the pH of the water around the soil? You can make your own pH paper, test the pH of the soil, add water, then test the pH of the water. Are the two values the same? If not, is there a relationship between them?

Ideas for Projects About Living Things

  • What effect does soap in water have on plants? Is the effect the same at very low soap concentrations as compared with high concentrations?
  • How much plant food is too much?
  • Are dogs (cats/fish/etc.) colorblind? If so, is the lack of color perception compensated by better light/dark vision?
  • What types of words do babies learn to speak first?
  • Are goldfish water chemicals really necessary or are they an unneeded expense?
  • Can you graft a tomato plant onto a potato plant?
  • Do plants react to the presence of other plants? music? different colored light?
  • Will chilling an onion before cutting it keep you from crying?
  • Does catnip repel cockroaches better than DEET?
  • What percentage of an orange is water?
  • Are night insects attracted to lamps because of heat or light?
  • Can you make Jello using fresh pineapples instead of canned pineapples?
  • Does the presence of detergent in water affect plant growth?
  • Does magnetism affect the growth of plants?
  • Do the same types of mold grow on all types of bread?
  • Does light affect the rate at which foods spoil?
  • Can you use a household water filter to remove flavor or color from other liquids?
  • Is the nutritional content of different brands of a vegetable (e.g., canned peas) the same?
  • How do different factors affect seed germination? Factors that you could test include the intensity, duration, or type of light, the temperature, the amount of water, the presence/absence of certain chemicals, or the presence/absence of soil. You can look at the percentage of seeds that germinate or the rate at which seeds germinate.
  • Is a seed affected by its size? Do different size seeds have different germination rates or percentages? Does seed size affect the growth rate or final size of a plant?
  • How does cold storage affect the germination of seeds? Factors you can control include the type of seeds, length of storage, temperature of storage, and other variables, such as light and humidity.
  • What conditions affect the ripening of fruit? Look at ethylene and enclosing a fruit in a sealed bag, temperature, light, or nearness to other pieces or fruit.
  • How close does a plant have to be to a pesticide for it to work? What factors influence the effectiveness of a pesticide (rain? light? wind?)? How much can you dilute a pesticide while retaining its effectiveness? How effective are natural pest deterrents?

Ideas for Physical Projects

  • What paper airplane design flies the farthest? stays aloft the longest?
  • What soils best support structures, such as buildings?
  • What materials glow under black light? Can you use the UV light to find invisible, possibly smelly, stains in your carpet or elsewhere in your house?
  • Do white candles burn at a different rate than colored candles?
  • How does the shape of an ice cube affect how quickly it melts?
  • Do different brands of popcorn leave different amounts of unpopped kernels?
  • How accurately do egg producers measure eggs?
  • How do differences in surfaces affect the adhesion of tape?
  • Are all potato chips equally greasy?
  • Does the power of a microwave affect how well it makes popcorn?
  • Do all brands of diapers absorb the same amount of liquid? Does it matter what the liquid is (water as opposed to juice or... um.. urine)?
  • How are different soils affected by erosion? You can make your own wind or water and evaluate the effects on soil. If you have access to a very cold freezer, you can look at the effects of freeze and thaw cycles.

More Science Fair Project Ideas

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Your Citation
Helmenstine, Anne Marie, Ph.D. "8th Grade Science Fair Project Ideas." ThoughtCo, Apr. 5, 2023, thoughtco.com/8th-grade-science-fair-projects-609030. Helmenstine, Anne Marie, Ph.D. (2023, April 5). 8th Grade Science Fair Project Ideas. Retrieved from https://www.thoughtco.com/8th-grade-science-fair-projects-609030 Helmenstine, Anne Marie, Ph.D. "8th Grade Science Fair Project Ideas." ThoughtCo. https://www.thoughtco.com/8th-grade-science-fair-projects-609030 (accessed May 27, 2023).