Hey there, future scientist! Are you ready to explore, discover, and have lots of fun? This collection of 5th grade science fair project ideas is made just for you.
Each idea is easy to follow, uses simple materials (many from around the house), and helps you learn something cool about the world. Whether you love plants, rockets, slime, or experiments you can do in the kitchen — there’s something here to spark your curiosity!
You’ll find projects grouped by topic and each idea includes a short plan: a question to ask, a guess (that’s your hypothesis), simple steps to test it, the materials you need, and what you’ll learn.
Use the experiment template to keep notes and take pictures — judges love clear steps and real results!
Don’t worry if your experiment doesn’t go exactly like your guess — that’s how real scientists learn. So pick a project you like, ask an adult for help when needed, and have fun discovering new things. Let’s get started with awesome 5th grade science fair project ideas!
How to use this article
- Read the short intro and tips below.
- Pick an idea that sounds fun.
- Follow the simple steps in each idea (Hypothesis → What to do → Materials → What you’ll learn).
- Use the presentation tips near the end to make a neat board or poster.
Quick tips before you start
- Pick a project that excites you — you’ll work better when you’re curious!
- Keep it safe: ask an adult for help with hot items, sharp tools, or chemicals.
- Use simple measurements (cups, spoons, Rulers in centimeters).
- Take photos and write down results — science loves evidence!
Must Read: 149+ Fun Honesty Activities for Kids — Simple, & Effective Ideas
A simple experiment template you can reuse
- Question / Title: What you want to find out.
- Hypothesis: Your guess (example: “I think plant A will grow faster than plant B.”)
- Method: Short steps to test it.
- Materials: What you need.
- Results: What happened.
- Conclusion: What you learned.
149+ 5th grade science fair project ideas
Below are 200 project ideas with short plans. Each idea includes a hypothesis idea, what to do, materials, and what you’ll learn. Ready? Let’s go!
Biology & Plants (1–30)
- Which plant grows fastest with sugar or salt?
- Hypothesis: Plants with sugar will grow faster than those with salt.
- What to do: Water three identical seedlings: plain water, sugar water, salt water. Measure growth for 2 weeks.
- Materials: Seedlings, cups, sugar, salt, ruler.
- Learn: How different solutions affect plant growth.
- Do plant roots grow toward light or water?
- Hypothesis: Roots grow toward water more than light.
- What to do: Put seeds in transparent containers with water on one side and light on top; watch root direction.
- Materials: Transparent cups, seeds, water, flashlight.
- Learn: Root tropism (response to environment).
- Which soil type holds the most water?
- Hypothesis: Clay holds more water than sand.
- What to do: Add the same water to sand, clay, and potting soil; measure water retained after draining.
- Materials: Soil types, funnels, cups, measuring cup.
- Learn: Soil texture and water retention.
- How does music affect plant growth?
- Hypothesis: Plants grow more with soft music.
- What to do: Play different music styles to separate plants for weeks; measure growth.
- Materials: Plants, speakers, music playlists.
- Learn: Possible effects of sound on plants.
- Do ants prefer sweet or salty food?
- Hypothesis: Ants prefer sweet.
- What to do: Place small drops of sugar water and salty water on paper and count ants visiting each.
- Materials: Sugar, salt, paper plates, stopwatch.
- Learn: Animal behavior and preference tests.
- Which household liquid keeps cut flowers fresh longest?
- Hypothesis: Sugar water or soda works best.
- What to do: Put identical flower stems in different liquids and note how long until flowers wilt.
- Materials: Flowers, water, soda, bleach (dilute), sugar water.
- Learn: How dissolved substances affect flower life.
- Does seed germination change with temperature?
- Hypothesis: Warmth speeds germination.
- What to do: Keep seeds at different temperatures and record how fast they sprout.
- Materials: Seeds, trays, thermometer, heat source, refrigerator.
- Learn: Temperature effect on seeds.
- How does salt affect earthworms?
- Hypothesis: Worms avoid salt.
- What to do: Create a container half with damp soil and half with damp soil + salt; watch where worms go.
- Materials: Worms, soil, salt, container.
- Learn: Animal response to salt.
- Do different liquids affect seed sprout color?
- Hypothesis: Colored water changes stem color.
- What to do: Put white flowers or celery in colored water and watch color move up.
- Materials: Celery, food coloring, clear cups, water.
- Learn: Capillary action in plants.
- Which light color helps plants grow best?
- Hypothesis: Blue light helps growth most.
- What to do: Use colored cellophane over lamps for different plants; compare growth.
- Materials: Lamps, cellophane, plants.
- Learn: Light wavelength and photosynthesis.
- Are earthworms more active in wet or dry soil?
- Hypothesis: Wet soil makes earthworms more active.
- What to do: Put worms in wet vs. dry soil and observe movement.
- Materials: Worms, soil, spray bottle, timer.
- Learn: Moisture needs of soil organisms.
- How do different liquids affect seed germination?
- Hypothesis: Plain water works best.
- What to do: Soak seeds in water, milk, soda, and juice then plant and observe.
- Materials: Seeds, liquids, pots.
- Learn: Liquids that help or hurt germination.
- Does exercise affect heart rate in kids?
- Hypothesis: Running raises heart rate more than walking.
- What to do: Measure heartbeat at rest, after walking, and after running.
- Materials: Stopwatch, notebook.
- Learn: How activity affects heart rate.
- Do colored lights change insect activity?
- Hypothesis: Bugs prefer certain colors.
- What to do: Set colored lights and count insects that appear at night.
- Materials: Colored LEDs, sticky traps, flashlight.
- Learn: Insects and light attraction.
- Can plants grow in different types of milk?
- Hypothesis: Milk harms plants.
- What to do: Water plants with diluted milk, regular water, and record growth.
- Materials: Plants, milk, water, measuring cup.
- Learn: What plants need to grow.
- How does sugar water affect bean sprouts?
- Hypothesis: Too much sugar slows growth.
- What to do: Give bean sprouts water with low, medium, high sugar; measure height.
- Materials: Beans, cups, sugar.
- Learn: Effects of sugars on plant growth.
- Do seeds grow faster in rainwater or tap water?
- Hypothesis: Rainwater is better.
- What to do: Plant seeds and water with rainwater vs. tap water; compare growth.
- Materials: Rainwater, tap water, seeds, pots.
- Learn: Water quality matters.
- Which common fruits attract the most fruit flies?
- Hypothesis: Banana attracts most.
- What to do: Put pieces of different fruits in jars and count flies each day.
- Materials: Fruit pieces, jars, mesh lids.
- Learn: Fruit ripeness and insect attraction.
- Can you clean polluted soil with plants? (Phytoremediation test)
- Hypothesis: Some plants remove pollutants.
- What to do: Plant in soil with safe dye/pellet pollutants and see if soil condition improves compared to control.
- Materials: Plants, soil, safe dye or biodegradable marker.
- Learn: Plants can help clean soil.
- How long do different seeds stay alive in storage?
- Hypothesis: Cool dry storage keeps seeds alive longer.
- What to do: Store seeds in different conditions; test germination after weeks.
- Materials: Seeds, envelopes, fridge, warm spot.
- Learn: Seed viability.
- Do different drinks change tooth enamel color?
- Hypothesis: Cola stains more than milk.
- What to do: Use eggshells as tooth enamel, soak in drinks, note color change.
- Materials: Eggshells, cola, juice, milk, cups.
- Learn: Effects of drinks on teeth.
- Do plants grow better with compost or fertilizer?
- Hypothesis: Compost helps most.
- What to do: Plant same seeds with compost, chemical fertilizer, and plain soil. Measure growth.
- Materials: Compost, fertilizer, soil, pots, seeds.
- Learn: Soil enrichment types.
- What color flower attracts the most bees?
- Hypothesis: Bright yellow draws more bees.
- What to do: Use colored paper flowers with sugar water and count bee visits.
- Materials: Paper flowers, sugar water, ruler.
- Learn: Pollinator preferences.
- How do spiders react to vibrations?
- Hypothesis: Spiders respond to vibration quickly.
- What to do: Gently tap a spider web frame and measure reaction time. (Observe only; don’t harm spiders!)
- Materials: Spider web frame (natural), stopwatch.
- Learn: Sensory behavior of spiders.
- Can fungi (mold) grow on different breads faster?
- Hypothesis: Moist bread molds faster.
- What to do: Leave different bread slices in sealed bags and note mold growth days.
- Materials: Bread types, plastic bags, marker.
- Learn: Conditions for mold growth.
- Which houseplant cleans air best?
- Hypothesis: Spider plant cleans air well.
- What to do: Measure smell or use a simple air-quality indicator (like observing a tea-light smoke in presence of plant) — or show plant health after smoke exposure.
- Materials: Houseplants, smudge source (very small, with adult help), observation sheet.
- Learn: Plants and air quality.
- How does light affect the time it takes for lettuce to wilt?
- Hypothesis: More light speeds wilting.
- What to do: Place lettuce leaves in different light levels and check freshness over days.
- Materials: Lettuce, lights, paper towels.
- Learn: Light and water loss.
- Do seeds sprout better when shaken daily?
- Hypothesis: Shaking may disturb roots and slow sprouting.
- What to do: Shake one set of seeds daily, keep another still; compare sprouting.
- Materials: Seeds, trays, water.
- Learn: Disturbance effects on seedlings.
- Which household surfaces have the most bacteria?
- Hypothesis: Kitchen sponge has most.
- What to do: Swab surfaces and grow cultures on petri dishes (use safe agar kits and adult supervision).
- Materials: Agar plates kit, swabs, safe method, adult.
- Learn: Microbes are everywhere; hygiene importance.
- Can plants grow under different pillow stuffing materials?
- Hypothesis: Natural stuffing helps more than synthetic.
- What to do: Plant seeds in soil mixed with shredded cotton, foam bits, or paper; observe growth.
- Materials: Seeds, soil, stuffing materials.
- Learn: Soil aeration and growth.
Chemistry
- Which dissolves sugar faster: hot or cold water?
- Hypothesis: Hot water dissolves faster.
- What to do: Time sugar dissolving in hot vs cold water.
- Materials: Cups, sugar, thermos, stopwatch.
- Learn: Temperature and solubility.
- Does salt change the boiling point of water?
- Hypothesis: Salt raises boiling point.
- What to do: Boil plain water and salted water; compare temperatures (with adult help).
- Materials: Pot, stove (adult), salt, thermometer.
- Learn: Boiling point elevation.
- How does pH of soda compare to water and juice?
- Hypothesis: Soda is more acidic.
- What to do: Use pH strips to test different drinks.
- Materials: pH strips, cola, water, orange juice.
- Learn: Acids, bases, and pH.
- Which brand of antacid neutralizes stomach acid best?
- Hypothesis: Some brands react faster.
- What to do: Use vinegar as “acid” and test different antacids with pH strips.
- Materials: Vinegar, antacids, pH strips.
- Learn: Acid neutralization.
- How does temperature affect reaction speed (baking soda + vinegar)?
- Hypothesis: Warmer liquid reacts faster.
- What to do: Mix baking soda and vinegar at different temperatures, measure fizzing time.
- Materials: Baking soda, vinegar, cups, thermometer.
- Learn: Temperature and reaction rates.
- Can you make a rainbow with different liquids? (Density column)
- Hypothesis: Dense liquids stay at bottom.
- What to do: Layer honey, dish soap, water, oil, and rubbing alcohol to make colorful layers.
- Materials: Honey, dish soap, water, oil, food coloring, clear glass.
- Learn: Liquid density.
- How does surface area change reaction time? (Alka-Seltzer)
- Hypothesis: Powder reacts faster than tablet.
- What to do: Drop tablet vs crushed tablet in water and time fizz.
- Materials: Alka-Seltzer, water, mortar (adult), stopwatch.
- Learn: Surface area and reaction speed.
- Which household cleaner removes stains best?
- Hypothesis: One cleaner is better.
- What to do: Stain identical fabric squares with ketchup, treat with different cleaners, compare.
- Materials: Fabric squares, stains, cleaners.
- Learn: Cleaning chemistry.
- How does temperature affect viscosity (honey)?
- Hypothesis: Honey flows faster when warm.
- What to do: Drip honey down a sloped tray at warm and cool temps and time.
- Materials: Honey, tray, thermometer.
- Learn: Viscosity and temperature.
- Do different metals rust faster in saltwater?
- Hypothesis: Some metals rust quicker.
- What to do: Put different metal pieces in saltwater and record rust after days.
- Materials: Metal nails (iron, steel), salt, water, jars.
- Learn: Corrosion and environment.
- Can you make invisible ink with household items?
- Hypothesis: Lemon juice works as invisible ink.
- What to do: Write with lemon juice and hold paper near heat to reveal writing (adult supervision).
- Materials: Lemon juice, paper, lamp or iron (adult).
- Learn: Oxidation and organic compounds.
- Which fabric dries fastest?
- Hypothesis: Synthetic fabrics dry faster.
- What to do: Wet small fabric pieces and time drying under same conditions.
- Materials: Fabric samples, timer.
- Learn: Fiber types and moisture.
- How does soap help remove oil from water?
- Hypothesis: Soap breaks oil into tiny droplets.
- What to do: Add oil to water, add soap, and watch dispersion; use food coloring for visibility.
- Materials: Oil, water, soap, bowls.
- Learn: Emulsification.
- Which common liquids freeze fastest?
- Hypothesis: Pure water freezes faster than sugary drinks.
- What to do: Place cups with water, salt water, soda into freezer and check freeze time.
- Materials: Freezer, drinks, cups, thermometer.
- Learn: Freezing point changes.
- Does sugar cause yeast to make more bubbles?
- Hypothesis: Sugar increases yeast activity.
- What to do: Mix yeast with water-only vs yeast + sugar; watch bubble amount.
- Materials: Yeast, sugar, bottles, balloons.
- Learn: Fermentation basics.
- Which common kitchen item is most alkaline?
- Hypothesis: Baking soda is alkaline.
- What to do: Test pH of soap, baking soda solution, lemon, and vinegar using pH strips.
- Materials: pH strips, household items.
- Learn: Acid vs base.
- How does cooking change egg proteins?
- Hypothesis: Heat changes egg white from clear to white.
- What to do: Cook one egg and compare raw vs cooked texture and color.
- Materials: Eggs, stove (adult).
- Learn: Protein denaturation.
- Can you make a non-Newtonian fluid (oobleck) and test its properties?
- Hypothesis: It acts like both solid and liquid.
- What to do: Mix corn starch & water and poke quickly vs slowly.
- Materials: Corn starch, water, bowl.
- Learn: Non-Newtonian fluids.
- Which juice attracts more fruit flies?
- Hypothesis: Sweet juice attracts more.
- What to do: Place different juices in jars and count flies.
- Materials: Juices, jars, mesh lids.
- Learn: Insect attraction and sugar.
- Do antacids work better crushed or whole?
- Hypothesis: Crushed works faster.
- What to do: Put whole and crushed antacid into vinegar and measure fizz.
- Materials: Antacid, vinegar, timer.
- Learn: Surface area and reaction rate.
- How does salt affect ice melting?
- Hypothesis: Salt melts ice faster.
- What to do: Put salt on ice and measure melting speed vs plain ice.
- Materials: Ice cubes, salt, tray, timer.
- Learn: Freezing point depression.
- Which liquid evaporates fastest at room temperature?
- Hypothesis: Alcohol evaporates faster than water.
- What to do: Put equal amounts of different liquids on dishes and time disappearance.
- Materials: Small plates, liquids (water, rubbing alcohol, cooking oil).
- Learn: Evaporation rates.
- Does vinegar clean pennies better than ketchup?
- Hypothesis: Vinegar cleans better.
- What to do: Soak pennies in vinegar, ketchup, and soapy water; compare shine.
- Materials: Pennies, cleaning liquids, toothbrush.
- Learn: Acid action on metals.
- How does temperature affect solubility of sugar in water?
- Hypothesis: Warm water dissolves more sugar.
- What to do: Add sugar to warm and cold water until saturation and compare amounts.
- Materials: Sugar, thermometers, cups, stove (adult).
- Learn: Solubility and temperature.
- Can you make a battery from a lemon?
- Hypothesis: Lemon can power a small LED.
- What to do: Insert copper and zinc nails into lemon and connect wires to LED.
- Materials: Lemon, copper coin/wire, zinc nail, LED, wires.
- Learn: Basic electrochemistry.
- Which detergent produces the most bubbles?
- Hypothesis: Dish soap makes most bubbles.
- What to do: Mix equal soap in water, shake, and measure foam height.
- Materials: Different soaps, bottles, measuring cup.
- Learn: Surfactants and foam.
- How does oil pollution affect water plants?
- Hypothesis: Oil harms plants.
- What to do: Add a thin layer of oil to water with aquatic plants and watch health (small scale, safe oil amounts).
- Materials: Small container, water plant, oil.
- Learn: Pollution effects.
- Does sugar make crystals faster than salt? (Crystal growth)
- Hypothesis: Sugar forms crystals faster.
- What to do: Make saturated solutions of sugar and salt and let them evaporate to form crystals.
- Materials: Sugar, salt, jars, string.
- Learn: Crystallization.
- How does temperature change the color of a pH indicator (red cabbage juice)?
- Hypothesis: Color change works at many temperatures.
- What to do: Make cabbage juice and add acid/base at warm and cool temperatures to compare color change.
- Materials: Red cabbage, blender, strainer, vinegar, baking soda.
- Learn: Natural pH indicators.
- Can you make a glowing solution with a safe tonic water experiment?
- Hypothesis: Tonic water glows under black light.
- What to do: Put tonic water in cup and shine a black light to show fluorescence.
- Materials: Tonic water, black light, cup.
- Learn: Fluorescence basics.
Physics & Motion
- Which paper plane design flies the farthest?
- Hypothesis: One design glides farther.
- What to do: Fold different plane designs and test flight distance.
- Materials: Paper, measuring tape.
- Learn: Aerodynamics.
- How does weight affect pendulum period?
- Hypothesis: Weight does not change period much.
- What to do: Make pendulums with same string length but different weights; time swings.
- Materials: String, weights, stopwatch.
- Learn: Pendulum physics.
- Which material insulates heat best?
- Hypothesis: Foam insulates better than cloth.
- What to do: Wrap hot water bottles in different materials and measure temperature drop.
- Materials: Bottles, materials (foam, wool, cotton), thermometer.
- Learn: Heat insulation.
- Can you build a simple electromagnet?
- Hypothesis: More coils make a stronger magnet.
- What to do: Wrap wire around nail, connect to battery, and pick up paperclips. Change coil number.
- Materials: Nail, insulated wire, battery, paperclips.
- Learn: Electromagnetism.
- How does surface area affect air resistance (fall time)?
- Hypothesis: Larger area falls slower.
- What to do: Drop crumpled and flat paper from same height and time.
- Materials: Paper, ruler, stopwatch.
- Learn: Air resistance.
- Which balloon rocket goes fastest?
- Hypothesis: Bigger balloons go faster.
- What to do: Tape straw to balloon, thread string, release and measure speed.
- Materials: Balloons, straw, string, tape, stopwatch.
- Learn: Thrust and Newton’s laws.
- How does friction change with surface type?
- Hypothesis: Carpet causes more friction than tile.
- What to do: Pull same weight on different surfaces and measure force with spring scale (or time).
- Materials: Toy car, ramps, different surfaces.
- Learn: Friction.
- Can you make a working periscope?
- Hypothesis: Angled mirrors let you see around corners.
- What to do: Build cardboard periscope with two mirrors and test.
- Materials: Cardboard tube, two small mirrors, tape.
- Learn: Light reflection.
- Which cup shape keeps a cold drink cold longest?
- Hypothesis: Tall thin cups keep cold better.
- What to do: Put equal cold liquid in cups and measure temperature over time.
- Materials: Different cups, thermometer.
- Learn: Surface area and heat transfer.
- How does length of string change pendulum speed?
- Hypothesis: Longer pendulum swings slower.
- What to do: Make pendulums of different lengths and time swings.
- Materials: String, weight, stopwatch.
- Learn: Pendulum period depends on length.
- Which magnet strength lifts more paperclips?
- Hypothesis: Bigger magnet picks more.
- What to do: Use different magnets to pick up paperclips and count.
- Materials: Magnets, paperclips.
- Learn: Magnetic strength comparison.
- How does incline angle affect speed of a rolling ball?
- Hypothesis: Steeper slope → faster speed.
- What to do: Roll ball down different angle ramps and time.
- Materials: Ball, ramp, protractor, stopwatch.
- Learn: Gravity and motion.
- Can you make a parachute that slows fall best?
- Hypothesis: Bigger parachute slows more.
- What to do: Make parachutes of different sizes and drop small toys; time descent.
- Materials: Plastic bags, string, small toy.
- Learn: Drag and parachute design.
- How does temperature affect sound speed?
- Hypothesis: Sound travels slightly faster in warm air.
- What to do: Clap and measure time between clap and echo at different temperatures (approximate).
- Materials: Open space, thermometer, timer (approximate method).
- Learn: Sound and temperature.
- Which shape is strongest under weight: triangle vs square?
- Hypothesis: Triangle is stronger.
- What to do: Build small bridges from straws in shapes and add weight until collapse.
- Materials: Straws, tape, small weights.
- Learn: Structural strength.
- Can you build a homemade thermometer?
- Hypothesis: Air expands and moves colored water up a straw when warm.
- What to do: Make glass bottle with colored water and straw; watch water level change with temperature.
- Materials: Bottle, straw, water, food coloring, clay.
- Learn: Thermal expansion.
- How does temperature affect battery life?
- Hypothesis: Cold reduces battery voltage.
- What to do: Put identical batteries in different temps and measure voltage with multimeter (adult help) or test lamp brightness.
- Materials: Batteries, small bulb, fridge, thermometer.
- Learn: Temperature and battery performance.
- Which material makes the best sound absorber?
- Hypothesis: Foam absorbs sound well.
- What to do: Clap in front of different materials and rate loudness (or measure with sound meter app).
- Materials: Foam, cloth, cardboard, phone sound meter app.
- Learn: Sound absorption.
- Can you make a solar oven and test which foods cook faster?
- Hypothesis: Dark-colored foods heat faster.
- What to do: Build a box solar oven and test marshmallow melting vs other foods.
- Materials: Pizza box, foil, plastic wrap, black paper, thermometer.
- Learn: Solar energy and heat trapping.
- How does changing length of a guitar string change pitch?
- Hypothesis: Shorter string → higher pitch.
- What to do: Make a simple string instrument and pluck at different lengths; compare sounds.
- Materials: Rubber bands, box, ruler.
- Learn: Sound frequency and string vibration.
- Which paper absorbs more water quickly?
- Hypothesis: Paper towel absorbs more than printer paper.
- What to do: Drop equal water amounts on different paper and measure absorption time.
- Materials: Papers, water, timer.
- Learn: Absorbent materials.
- How does angle of sunlight affect shadow length?
- Hypothesis: Noon sun makes shortest shadows.
- What to do: Mark object shadow length at different times of day.
- Materials: Object, chalk, ruler, notebook.
- Learn: Earth’s rotation and sun angle.
- Can you build a simple seismograph?
- Hypothesis: A suspended pen will record vibrations on paper.
- What to do: Make a pendulum pen that writes on paper as surface is tapped; simulate small quakes.
- Materials: Box, paper roll, pen, string, clamp.
- Learn: Recording vibrations.
- Does temperature change bouncing height of a ball?
- Hypothesis: Cold makes ball less bouncy.
- What to do: Bounce ball stored in fridge vs room temp and measure bounce height.
- Materials: Ball, ruler, fridge, stopwatch.
- Learn: Material elasticity and temperature.
- Which toy car wheels give best distance?
- Hypothesis: Larger wheels may roll farther.
- What to do: Test toy cars with different wheels down same ramp and measure distance.
- Materials: Toy cars, ramps, measuring tape.
- Learn: Wheel size and rolling efficiency.
- Can you make a water clock?
- Hypothesis: Water level drops at steady rate when flow is constant.
- What to do: Use two connected bottles to make timed dripping and mark time intervals.
- Materials: Bottles, tubing, marker.
- Learn: Ancient timekeeping and flow rates.
- How do magnets interact through different materials?
- Hypothesis: Magnet strength weakens through thick material.
- What to do: Try picking up paperclips with magnet through paper, wood, plastic.
- Materials: Magnets, materials, paperclips.
- Learn: Magnetic field shielding.
- Which shapes cut the least drag in water?
- Hypothesis: Smooth shapes have less drag.
- What to do: Pull different shaped objects through water and feel resistance or time movement.
- Materials: Water tank (tub), objects, stopwatch.
- Learn: Hydrodynamics basics.
- Can you measure reaction time with a ruler drop test?
- Hypothesis: Older kids have faster reaction times.
- What to do: Drop ruler and have volunteer catch; measure distance to calculate reaction time.
- Materials: Ruler, volunteer, calculator.
- Learn: Human reaction speeds.
- How does humidity affect static electricity?
- Hypothesis: Dryer air increases static.
- What to do: Rub balloon on hair and test static at different humidity days/rooms.
- Materials: Balloon, hair, humidifier (optional).
- Learn: Static charge and humidity.
- Which bridge design holds most weight: truss vs beam?
- Hypothesis: Truss supports more.
- What to do: Build small bridge models and add weights until they break.
- Materials: Popsicle sticks, glue, weights.
- Learn: Engineering design.
- Can you build a simple electric motor?
- Hypothesis: Coil + magnet + battery makes motor spin.
- What to do: Make coil, balance on supports, place magnet and battery to spin.
- Materials: Wire, battery, magnet, support.
- Learn: Electromagnetism and motors.
- How does temperature change density of air (balloon experiment)?
- Hypothesis: Warm air makes balloon expand more.
- What to do: Put balloon near warm and cold air and observe size change.
- Materials: Balloons, heat source (adult), fridge.
- Learn: Air density and temperature.
- Which homemade rocket (baking soda vs vinegar) goes higher?
- Hypothesis: One combination produces more thrust.
- What to do: Launch small bottle rockets using vinegar + baking soda vs yeast + sugar and compare.
- Materials: Plastic bottles, vinegar, baking soda, safety gear, adult.
- Learn: Reaction thrust and safety.
- How does color affect how hot a surface gets in sun?
- Hypothesis: Dark surfaces get hotter.
- What to do: Place black and white paper outside and measure temperature after 30 minutes.
- Materials: Colored paper, thermometer, sun.
- Learn: Absorption of light and heat.
- Can you make a Morse code telegraph using sound?
- Hypothesis: Beeps can transmit messages.
- What to do: Tap out messages with a buzzer and have someone decode.
- Materials: Buzzer, battery, switch, paper for code.
- Learn: Communication basics.
- Which material makes the best ramp for speed (car experiment)?
- Hypothesis: Smooth plastic gives fastest speed.
- What to do: Use ramp surfaces like carpet, tile, plastic and race toy cars.
- Materials: Toy cars, ramp, surface materials.
- Learn: Surface friction and speed.
- How does length of straw affect pitch when blown across?
- Hypothesis: Shorter straw → higher pitch.
- What to do: Cut straws to lengths and blow across to compare sound.
- Materials: Straws, scissors.
- Learn: Resonance and pitch.
- Can you measure speed of a rolling marble with photo timing? (simple)
- Hypothesis: Steeper ramp → faster marble.
- What to do: Use two stopwatches or timing gates (phone apps) to find speed down ramps.
- Materials: Marble, ramp, phone stopwatch.
- Learn: Speed calculation.
- How does load position affect balance on a seesaw?
– Hypothesis: Closer to pivot needs more weight to balance.
– What to do: Test weights at varying distances on a plank supported at center.
– Materials: Plank, fulcrum, weights.
– Learn: Levers and torque.
Environmental Science & Earth
- Which material absorbs oil best from water?
- Hypothesis: Sponges soak oil better.
- What to do: Add oil to water and try cotton, sponge, and paper towel to remove oil.
- Materials: Oil, water, absorbents, tray.
- Learn: Pollution cleanup.
- Do trees reduce temperature under their shade?
- Hypothesis: Shade makes it cooler.
- What to do: Measure temperature under tree shade vs open area at same time.
- Materials: Thermometer, sunny day.
- Learn: Trees cool environment.
- How does composting speed change with green vs brown material?
- Hypothesis: Mixed green and brown composts faster.
- What to do: Make small compost piles varying green/brown balance and record temperature/activity.
- Materials: Food scraps, leaves, container, thermometer.
- Learn: Composting basics.
- Which surface warms faster: grass or asphalt?
- Hypothesis: Asphalt warms faster.
- What to do: Measure surface temperature of grass and nearby road.
- Materials: Thermometer or infrared (adult help).
- Learn: Heat absorption of surfaces.
- Can you reduce water loss by mulching?
- Hypothesis: Mulch keeps soil moist longer.
- What to do: Water two pots, cover one with mulch; measure soil moisture over days.
- Materials: Pots, mulch, soil, watering can.
- Learn: Mulch and water conservation.
- How does litter affect plant growth?
- Hypothesis: Litter hurts growth.
- What to do: Place small litter around some seedlings and none around others; compare.
- Materials: Litter (paper only), pots, seeds.
- Learn: Pollution effects.
- Can algae grow faster in warm water than cool?
- Hypothesis: Warm water speeds algae.
- What to do: Put algae samples in warm vs cool containers and compare growth (safe algae).
- Materials: Algae sample (safe), jars, thermometer.
- Learn: Water temperature effects.
- Which style of window blinds keeps rooms coolest?
- Hypothesis: Reflective blinds reduce heat most.
- What to do: Put small model rooms with different blinds under lamp and measure temperature.
- Materials: Boxes, blinds materials, lamp, thermometer.
- Learn: Energy-saving methods.
- How long does paper take to decompose in soil? (Small sample test)
- Hypothesis: Thinner paper decomposes faster.
- What to do: Bury paper samples and dig up weekly to observe breakdown.
- Materials: Paper types, soil, markers.
- Learn: Biodegradation times.
- Do different types of mulch affect soil temperature?
- Hypothesis: Dark mulch warms soil more.
- What to do: Cover soil with different mulch and measure temperatures.
- Materials: Mulch types, thermometer.
- Learn: Mulch effects.
- Which recyclable material is most water-resistant?
- Hypothesis: Plastic resists water best.
- What to do: Put cardboard, paper, and plastic pieces in water and observe.
- Materials: Recyclables, water, tray.
- Learn: Material properties.
- How does acid rain (simulated) affect plant leaves?
- Hypothesis: Acid rain damages leaves.
- What to do: Spray diluted vinegar water on leaves at safe concentration and watch changes.
- Materials: Plants, vinegar, water, spray bottle.
- Learn: Pollution impact on plants.
- Can you build a small model of water filtration?
- Hypothesis: Layers of sand/charcoal clean dirty water.
- What to do: Pour dirty water through layers and compare clarity.
- Materials: Sand, gravel, activated charcoal, funnel.
- Learn: Filtration basics.
- Which fruit decomposes fastest on the ground?
- Hypothesis: Banana decomposes fast.
- What to do: Put fruit pieces on soil, cover lightly, and observe decay.
- Materials: Fruit pieces, soil, jar (or outdoor spot).
- Learn: Decomposition rates.
- How does slope affect soil erosion in a tray model?
- Hypothesis: Steeper slopes cause more erosion.
- What to do: Make soil slopes in trays and pour water to simulate rain; measure soil loss.
- Materials: Trays, soil, water, protractor.
- Learn: Erosion and land management.
- Do different teas decompose faster in soil?
- Hypothesis: Tea bags with less paper decompose faster.
- What to do: Bury tea bags and check weekly.
- Materials: Tea bags, soil, markers.
- Learn: Compostable vs not.
- How does time of day affect bird visits to a feeder?
- Hypothesis: Morning has more visits.
- What to do: Count bird visits at set times each day.
- Materials: Bird feeder, notebook, binoculars (optional).
- Learn: Animal daily patterns.
- Which biodegradable bag breaks down faster in soil?
- Hypothesis: Some branded bags degrade faster.
- What to do: Bury small pieces and check after weeks.
- Materials: Different bag samples, soil.
- Learn: Biodegradable products performance.
- Does watering frequency affect soil microbes? (Simple test)
- Hypothesis: Regular watering increases microbe activity.
- What to do: Compare soil smell and plant growth with different watering schedules.
- Materials: Soil pots, water, notebook.
- Learn: Soil health basics.
- Can you measure how much water a sponge holds at different sizes?
- Hypothesis: Bigger sponge holds more water proportionally.
- What to do: Soak sponges, squeeze and measure water held.
- Materials: Sponges, measuring cup, scale.
- Learn: Absorption capacity.
Engineering & Design
- Which bridge material is lightest but strongest?
- Hypothesis: Balsa wood may be strongest per weight.
- What to do: Build small bridge models from different materials and test weight capacity.
- Materials: Balsa, popsicle sticks, glue, weights.
- Learn: Strength-to-weight ratio.
- Can you design a bottle boat that floats longest with weight?
- Hypothesis: Wider boats hold more weight.
- What to do: Build boats from bottles and add weights until sinking.
- Materials: Plastic bottles, tape, weights.
- Learn: Buoyancy and hull design.
- Which paper airplane launcher sends planes farthest?
- Hypothesis: Elastic band launchers give more distance.
- What to do: Build launchers and compare distances.
- Materials: Elastic bands, cardboard, tape.
- Learn: Energy transfer.
- How does length of straw in a straw rocket affect distance?
- Hypothesis: Longer straw may travel farther.
- What to do: Blow into different straw lengths and measure travel distance.
- Materials: Straws, tape, measuring tape.
- Learn: Air pressure and projectile motion.
- Which design of domino chain falls fastest?
- Hypothesis: Tighter spacing makes faster chain.
- What to do: Set up dominoes with different spacing and measure cascade speed.
- Materials: Dominoes, ruler, stopwatch.
- Learn: Chain reaction timing.
- Can you build a simple robot arm from cardboard that picks up things?
- Hypothesis: Proper lever lengths improve grip.
- What to do: Make arm with string pulleys and test pick-up.
- Materials: Cardboard, string, tape, small objects.
- Learn: Levers and simple machines.
- Which type of wheel axle is most efficient?
- Hypothesis: Lubricated axles roll farther.
- What to do: Test toy car axles with and without lubricant and measure distance.
- Materials: Toy cars, oil, ramp.
- Learn: Friction reduction.
- How does shape of paper cup affect stability on water?
- Hypothesis: Wide base is more stable.
- What to do: Float cups of different shapes and add weight until tipping.
- Materials: Paper cups, water, small weights.
- Learn: Stability and center of gravity.
- Can you design a simple water wheel to lift small weights?
- Hypothesis: Larger paddles produce more torque.
- What to do: Build wheel from spoons or cardboard and let water flow to lift a weight.
- Materials: spoons/cardboard, axle, water source, string, weight.
- Learn: Water energy conversion to mechanical work.
- Which kite shape flies best in light wind?
- Hypothesis: Diamond kite flies best in light wind.
- What to do: Make different shapes and test flight in light breeze.
- Materials: Paper, sticks, glue, string.
- Learn: Lift and kite design.
- How does propeller blade angle affect fan push?
- Hypothesis: Steeper blades push more air.
- What to do: Make simple propellers with different angles and measure airflow with light paper.
- Materials: Cardboard, stick, fan motor (toy), paper.
- Learn: Blade pitch and airflow.
- Which lid design keeps a container leak-free?
- Hypothesis: Screw lids leak less.
- What to do: Test lids on bottles leaning at angles and see leak amount.
- Materials: Bottles, different lids, measuring cup.
- Learn: Sealing design.
- Can you build a solar-powered toy car?
- Hypothesis: Sunlight powers small motor well.
- What to do: Attach small solar cell to motor and wheels, test in sun.
- Materials: Solar cell kit, small motor, wheels.
- Learn: Solar energy to motion.
- Which straw structure supports most weight: triangle vs square frames?
- Hypothesis: Triangle frames are stronger.
- What to do: Construct frames from straws and add weights until collapse.
- Materials: Straws, connector (clay/tape), weights.
- Learn: Shape strength.
- How do different glue types affect joint strength?
- Hypothesis: Wood glue stronger than school glue.
- What to do: Glue wood pieces with different glues and measure weight needed to pull apart.
- Materials: Wood pieces, glues, weights.
- Learn: Adhesive strength.
- Can you design a windshield wiper mechanism with a motor and lever?
- Hypothesis: Certain lever lengths create better sweep.
- What to do: Build small wiper system and test sweep angles.
- Materials: Motor, cardboard, wire, power source.
- Learn: Mechanism design.
- Which paper boat design carries the most coins?
- Hypothesis: Folded paper with wide base carries more.
- What to do: Fold different boats and add coins until sinking.
- Materials: Paper, coins, water tray.
- Learn: Buoyancy and shape effect.
- Can you design a trap that catches a rolling marble at certain speed?
- Hypothesis: Angled ramp plus cushion stops marble efficiently.
- What to do: Try different trap designs and measure stopping distance.
- Materials: Marble, ramps, cushions.
- Learn: Energy absorption.
- How does angle of solar panel affect power output?
- Hypothesis: Best angle faces noon sun directly.
- What to do: Put small solar panel at different angles and measure voltage.
- Materials: Small solar panel, multimeter (optional), sun.
- Learn: Optimal solar orientation.
- Can you build a balloon-powered car that travels fastest?
- Hypothesis: Streamlined car goes faster.
- What to do: Build balloon car bodies with different shapes and race them.
- Materials: Balloons, straws, bottle caps (wheels), tape.
- Learn: Drag and thrust.
Food Science & Everyday Chemistry
- Which cooking oil smokes at lower temperature?
- Hypothesis: Some oils smoke earlier.
- What to do: Heat small amounts under adult supervision and note smoke point.
- Materials: Different oils, stove (adult), thermometer.
- Learn: Smoke point and cooking safety.
- How does sugar concentration change freezing point in ice cream?
- Hypothesis: More sugar lowers freezing point.
- What to do: Make small ice cream batches with different sugars and texture test.
- Materials: Milk, sugar, freezer, bowls.
- Learn: Freezing points and sugars.
- Does stirring speed change melting time of chocolate?
- Hypothesis: Faster stirring spreads heat and melts faster.
- What to do: Melt chocolate with different stirring rates and time.
- Materials: Chocolate, double boiler (adult), spoon, timer.
- Learn: Heat transfer.
- Which grain expands most when cooked? (Rice, quinoa, barley)
- Hypothesis: Rice expands most.
- What to do: Cook equal volumes and measure after cooking.
- Materials: Grains, water, measuring cups, stove.
- Learn: Absorption and cooking.
- How does acidity affect gelatin setting?
- Hypothesis: Acidic fruits stop gelatin from setting well.
- What to do: Make gelatin with different fruit juices and compare set time/firmness.
- Materials: Gelatin mix, juices, cups.
- Learn: pH effect on proteins/gelatin.
- Can you make butter from cream and test time with shaking?
- Hypothesis: Faster shaking makes butter quicker.
- What to do: Shake cream in jar at different speeds/times and observe butter forming.
- Materials: Cream, jars, strainer, salt (optional).
- Learn: Emulsion breaking and fat separation.
- Which bread type traps most air during baking?
- Hypothesis: Yeast bread traps more air than quick bread.
- What to do: Bake small loaves and measure crumb density.
- Materials: Bread recipes, oven (adult), ruler.
- Learn: Leavening and texture.
- Does salt make vegetables cook faster?
- Hypothesis: Salt can change boiling point slightly and affect cooking speed.
- What to do: Boil vegetables with and without salt and compare tenderness times.
- Materials: Vegetables, pot, salt, timer.
- Learn: Cooking chemistry.
- Which kitchen sponge holds the most water after soaking?
- Hypothesis: Cellulose sponge holds more than synthetic.
- What to do: Soak sponges, squeeze into measuring cup, compare amounts.
- Materials: Sponges, measuring cup.
- Learn: Absorbent material comparison.
- Can you measure sugar content of fruit juices with a refractometer (or taste test scale)?
- Hypothesis: Some juices are sweeter.
- What to do: Use simple refractometer (if available) or do dilution tasting scale.
- Materials: Refractometer (optional), juices, spoons.
- Learn: Brix (sugar content) concept.
- How does sugar amount affect caramel color?
- Hypothesis: More sugar darkens faster.
- What to do: Heat sugar solutions with different concentrations and watch color change (adult).
- Materials: Sugar, pan, stove (adult), thermometer.
- Learn: Maillard reaction and caramelization.
- Does vinegar change cookie texture?
- Hypothesis: A little vinegar makes cookies cakier.
- What to do: Bake cookies with and without small vinegar amount and compare texture.
- Materials: Cookie ingredients, oven (adult).
- Learn: Acid’s role in baking.
- Which fruit ripens faster in a paper bag vs open air?
- Hypothesis: Paper bag traps ethylene and ripens fruit faster.
- What to do: Put banana in bag vs open plate and check daily.
- Materials: Fruit, paper bag.
- Learn: Ethylene and ripening.
- Can you make natural pH indicator from beet juice and test household liquids?
- Hypothesis: Beet juice changes color with pH.
- What to do: Extract beet juice and test vinegar, soap, soda.
- Materials: Beet, blender, strainer, liquids.
- Learn: Natural indicators.
- Which flour makes fluffiest pancakes? (All-purpose vs whole wheat)
- Hypothesis: All-purpose makes fluffier pancakes.
- What to do: Make pancakes with different flours and compare height and softness.
- Materials: Flours, stove (adult), measuring tools.
- Learn: Flour protein and texture.
- How does salt affect egg boiling time?
- Hypothesis: Salt may change boiling properties slightly.
- What to do: Boil eggs in salted vs plain water and compare cooking time needed for hard-boiled.
- Materials: Eggs, pot (adult), salt, timer.
- Learn: Boiling dynamics.
- Can you make edible water bubbles using gelatin?
- Hypothesis: Gelatin can form spheres that hold water.
- What to do: Use simple molecular gastronomy kit or gelatin method to form edible spheres (adult help).
- Materials: Gelatin, water, spoon, molds.
- Learn: Gel formation and food science.
- Which beverage cools body temperature faster on a hot day?
- Hypothesis: Cold water cools fastest.
- What to do: Measure perceived cooling (survey) after sipping different drinks on hot day (use safe methods).
- Materials: Drinks, volunteers, thermometer (optional).
- Learn: Rehydration and body cooling.
- How does sugar affect yeast bread rise height?
- Hypothesis: Some sugar feeds yeast and increases rise up to a point.
- What to do: Bake small doughs with varying sugar amounts and measure rise.
- Materials: Dough ingredients, oven (adult), measuring tools.
- Learn: Yeast feeding and baking.
- Which fruit juice ferments into alcohol fastest (safe small test)?
- Hypothesis: High sugar juices ferment faster.
- What to do: Mix juice with yeast in sealed bottles and observe CO₂ production (adult supervision; do not consume).
- Materials: Juice, yeast, bottles, balloons.
- Learn: Fermentation and gas production.
Space, Technology & Misc
- Can you model craters and study impact effects?
- Hypothesis: Bigger rocks make bigger craters.
- What to do: Drop different sized marbles into flour/sand trays and measure crater size.
- Materials: Flour/sand, marbles, ruler.
- Learn: Impact cratering.
- How does surface color affect heating by light (space model)?
- Hypothesis: Darker surfaces heat more in sunlight.
- What to do: Test small model surfaces in lamp and measure.
- Materials: Paint, lamp, thermometer.
- Learn: Albedo effect.
- Which material best blocks microwaves? (Use safe model & adult guidance)
- Hypothesis: Metal blocks microwaves.
- What to do: Use safe experiments with old microwave parts (adult) to show reflection (only adults should handle).
- Materials: Metal foil, microwave-safe containers (adult).
- Learn: Microwave shielding (safety focus).
- Can you test which smartphone screens show fingerprints most?
- Hypothesis: Glossy screens show more prints than matte.
- What to do: Touch different screens and observe fingerprint visibility under light.
- Materials: Screen samples (old phones/tablets), light.
- Learn: Surface properties.
- How does gravity affect water in a spinning bucket (centrifugal force demo)?
- Hypothesis: Spinning pushes water outward.
- What to do: Swing a bucket of water in a circle (adult help) to show water stays in when speed is right.
- Materials: Bucket, water, adult.
- Learn: Centripetal/centrifugal effects.
- Which snack expands most in microwave (popcorn vs rice cakes)? (Adult help)
- Hypothesis: Popcorn expands most.
- What to do: Microwave different snacks for the same time and observe expansion.
- Materials: Snacks, microwave (adult).
- Learn: Moisture and steam expansion.
- Can you build a paper sundial and tell time?
- Hypothesis: Sundial can show daytime hours.
- What to do: Make sundial with stick and mark shadow positions over day.
- Materials: Paper plate, stick, marker.
- Learn: Sun position and timekeeping.
- How does satellite dish shape focus signals? (Model experiment)
- Hypothesis: Parabolic shapes focus signals to a point.
- What to do: Use small parabolic dishes or foil and test where sound/light focuses.
- Materials: Foil, bowl, small speaker or flashlight.
- Learn: Focusing shapes.
- Which homemade telescope lens setup gives clearest image?
- Hypothesis: Larger lenses give clearer view.
- What to do: Try magnifying glasses at different distances to see objects far away.
- Materials: Magnifying glasses, cardboard tubes.
- Learn: Lenses and magnification.
- Can you simulate a rocket launch angle vs distance?
- Hypothesis: 45° often gives farthest distance.
- What to do: Launch small stomp rockets or paper rockets at different angles and measure.
- Materials: Paper rockets or stomp rocket kit, measuring tape.
- Learn: Projectile motion and angles.
Presenting Your Project — Simple Steps to a Great Board
- Title big and bold: include keyword like 5th grade science fair project ideas so judges know your topic.
- Use sections: Question, Hypothesis, Materials, Procedure, Results (with photos/charts), Conclusion.
- Add drawings or photos for steps.
- Use a neat font and bright colors. Emojis can’t go on the actual board, but your notes can be fun!
- Practice explaining your project in 1–2 minutes.
Safety & Ethical Notes
- Always ask an adult for help when using heat, chemicals, or tools.
- Don’t harm animals — observe without hurting them.
- Label any experiment that uses food or rot (mold tests) and keep them in sealed containers.
Must Read: 200 English Project Ideas for Kids — Fun & Easy Projects
Final Encouragement
You now have 200 amazing 5th grade science fair project ideas to choose from! Pick one you love, plan it using the template, and have fun exploring. Science is all about asking “why?” and testing your idea. Don’t worry if results surprise you — surprising results are where learning happens!
If you want, I can:
- Turn one idea you pick into a full step-by-step experiment report, with a printable poster layout and chart.
- Or make a short 2-minute presentation script you can read at the fair.
