1029 science project ideas, from class 1 to college.

What it shows

Water with more sugar dissolved in it is denser, so it sinks below water with less sugar. Layers of differently sweetened, coloured water stack up like a rainbow.

You will need

• Sugar and warm water
• Four food colours
• Four cups and a tall clear glass
• A spoon or a syringe (no needle) for pouring slowly

Safety: An adult should handle the warm water.

Take it further: Pour the layers in the opposite order and see what happens.

What it shows

Vinegar (an acid) reacts with baking soda (a base) and gives off carbon dioxide gas, which pushes the foam out. Real volcanoes erupt molten rock, so the model shows the shape of a volcano, not its cause.

You will need

• A small bottle inside a clay or papier-mâché mountain
• Baking soda
• Vinegar
• A drop of dishwash and red food colour
• A tray

Safety: Work on a tray or outdoors, and keep vinegar away from eyes.

What it shows

Red cabbage juice changes colour with acids and bases: pink or red in acids, purple when neutral, and blue, green or yellow in bases.

You will need

• Red cabbage leaves and hot water
• A strainer and clear cups
• Lemon juice, vinegar, baking soda solution, soap water and tap water

Safety: An adult should handle the hot water. Do not taste anything, and do not test bleach or toilet cleaners.

Take it further: Soak filter paper in the juice and dry it to make your own indicator paper.

What it shows

Two different metals in an acidic juice make an electric cell, turning chemical energy into electrical energy. One lemon gives less than one volt, so several are joined in series to light an LED.

You will need

• Four lemons or potatoes
• Copper strips or coins, and galvanised (zinc-coated) nails
• Wires with crocodile clips
• An LED and a multimeter

Safety: Do not eat the fruit afterwards.

Take it further: Does the distance between the metals, or the type of fruit, change the voltage?

What it shows

Iron rusts only when both air (oxygen) and water are present, and salt water speeds it up. Nails kept dry, or in boiled water sealed with a layer of oil, stay bright.

You will need

• Four iron nails and four test tubes or jars
• Tap water, salt water, boiled water and a little oil
• A drying agent such as anhydrous calcium chloride
• Labels

Safety: Wear gloves to handle calcium chloride and keep it away from eyes. An adult should boil the water.

What it shows

Many inks are mixtures of colours. As water climbs the paper, each colour travels a different distance, depending on how well it dissolves and how strongly it sticks to the paper.

You will need

• Filter paper or coffee filter strips
• Sketch pens of different brands
• A glass of water
• A pencil and clips

Take it further: Measure each colour’s distance and work out its Rf value: the distance moved by the colour divided by the distance moved by the water.

What it shows

An electric current splits water into hydrogen at the negative electrode and oxygen at the positive one. About twice as much hydrogen as oxygen collects, which matches the formula H₂O.

You will need

• A 9 V battery
• Two pencil leads or graphite rods as electrodes
• Water with baking soda dissolved in it
• Two small test tubes
• A plastic tray

Safety: Use baking soda, not common salt, which gives off chlorine gas. Keep flames away and use a battery only.

What it shows

pH measures how acidic or basic a solution is on a scale from 0 to 14, with 7 neutral. Universal indicator or pH paper shows the value by its colour.

You will need

• pH paper or universal indicator
• Samples: lemon juice, curd, milk, tea, soap water, baking soda solution, tap water
• Clear cups and droppers
• The colour chart

Safety: Do not taste the samples or test strong cleaners.

What it shows

Vitamin C reacts with iodine. When iodine solution is added drop by drop to a juice containing starch, the blue-black colour appears only after all the vitamin C is used up, so more drops mean more vitamin C.

You will need

• Iodine solution and starch solution
• Fresh and packaged juices
• A dropper or a burette
• A measuring cylinder and small beakers

Safety: Iodine stains and is harmful if swallowed: do not drink any sample, and work with your teacher.

What it shows

Soaps differ in how much lather they make. In hard water, calcium and magnesium salts react with soap to form scum, so less foam forms.

You will need

• Samples of different soaps
• Distilled water and tap water
• Test tubes with stoppers
• A ruler and a stopwatch

What it shows

An effervescent tablet dissolves faster in warm water, because the particles move faster and collide more often and with more energy. Crushing the tablet speeds it up too, by giving it more surface area.

You will need

• Effervescent antacid or vitamin tablets
• Water at three or four temperatures
• A thermometer and a stopwatch
• Clear cups

What it shows

Guava contains oxalate ions. Titrating extracts of raw, half-ripe and ripe guava with potassium permanganate shows how the amount of oxalate changes as the fruit ripens.

You will need

• Guavas at three stages of ripeness
• Potassium permanganate solution and dilute sulphuric acid
• A burette, a pipette and conical flasks
• Filter paper and a mortar and pestle

Safety: This uses an acid and an oxidiser: do it only in the school lab with your teacher, wearing goggles and gloves.

What it shows

Some adulterants show up with simple tests: starch in milk, paneer or khoa turns blue-black with iodine, and sawdust or brick powder in spices floats or settles when the powder is sprinkled on water.

You will need

• Samples of milk, paneer, turmeric and chilli powder
• Iodine solution
• Glasses of water
• A dropper and white tiles

Safety: Do not eat the tested samples. Tests that need strong acids must be done in the lab with your teacher.

What it shows

Turmeric contains a yellow dye called curcumin that turns reddish brown in a base such as soap water and stays yellow in an acid such as lemon juice. Home-made turmeric strips work like litmus paper and let you sort kitchen liquids into acids, bases and neutrals.

You will need

• 1 teaspoon turmeric powder (haldi)
• 2 tablespoons water or hand sanitiser (adult handles sanitiser)
• Strips of white blotting paper or coffee filter, about 1 cm by 5 cm, 10 strips
• Small cups of lemon juice, vinegar, soap water, baking soda water, plain water, milk
• A dropper or a clean straw
• An old newspaper to dry the strips on

Safety: Turmeric stains clothes and tables, so wear old clothes and work on newspaper. An adult must handle hand sanitiser if used, and nothing is tasted.

Take it further: Write a secret message on paper with baking soda water, let it dry, and brush it with turmeric water to reveal it in red.

What it shows

The red pigment in hibiscus (gudhal) petals is an anthocyanin that turns pink red in acids and greenish or dark in bases. By testing kitchen liquids you can build a colour chart that places each liquid roughly on a scale from strong acid to strong base.

You will need

• 5 to 6 fresh red hibiscus flowers (or dried petals from a tea shop)
• A cup of warm water (adult pours it)
• Six small transparent glasses or steel cups
• Lemon juice, vinegar, plain water, milk, baking soda water, washing soda or soap water
• A spoon and a dropper
• White paper for the chart and crayons or pencils

Safety: An adult must pour the warm water. Do not taste any of the test liquids once the petal extract is added, and wash hands after handling washing soda.

Take it further: Repeat with red cabbage, beetroot and rose petals, and compare which plant gives the clearest range of colours.

What it shows

Hot water dissolves far more sugar than cold water. As a very strong sugar solution cools and slowly loses water, the extra sugar comes out of solution as crystals that grow on a string, which is exactly how mishri is made.

You will need

• 2 cups sugar
• 1 cup water
• A clean glass jar
• A cotton thread and a pencil or stick
• A paper clip or clean washer as a weight
• A saucepan (adult only)
• Food colour, optional

Safety: An adult must boil the water and pour the hot syrup; the child only watches at that stage. Let the jar cool before touching it.

Take it further: Grow one jar in the fridge and one at room temperature and compare the crystal size after a week.

What it shows

Alum dissolves easily in hot water and much less in cold water. A saturated alum solution left in half an eggshell slowly deposits sparkling crystals on the shell wall, making a model of a geode, the hollow rocks lined with crystals that form in the same way underground.

You will need

• 3 to 4 tablespoons alum (fitkari) from a general store
• Half a cup of hot water (adult handles)
• Two clean, dry eggshell halves
• White glue and a small brush
• A little extra powdered alum for dusting
• Food colour, optional
• An egg carton to hold the shells level

Safety: An adult must handle the hot water and pour the solution. Alum is a kitchen and water-purifying chemical but must not be eaten; wash hands afterwards.

Take it further: Grow a second geode with sugar or with Epsom salt and compare the crystal shapes and growing speed.

What it shows

Each substance makes crystals of its own fixed shape: salt forms cubes, sugar forms slanted blocks, and alum forms pointed double pyramids. Looking at grains with a magnifier shows that crystals are not random lumps but neat, repeating shapes.

You will need

• A pinch each of table salt, sugar, alum powder and washing soda
• A magnifying glass or a mobile phone camera on zoom
• Black paper or a dark plate
• A toothpick for moving grains
• Pencil and paper for drawings

Safety: Keep the grains away from the mouth and eyes; washing soda is not for eating. Wash hands after the activity.

Take it further: Dissolve a little salt in water, let a drop dry on a dark plate in the sun and look at the new cubes that form.

What it shows

Dissolving gets faster when the water is warmer, when the liquid is stirred, and when the sugar is in smaller pieces. A fair test with a stopwatch shows which of these three has the biggest effect.

You will need

• Sugar cubes or equal spoons of sugar, 6 portions
• Six identical glasses
• Cold water, room-temperature water and warm water (adult pours warm)
• A spoon
• A stopwatch or a phone timer
• A notebook for the table

Safety: An adult must pour the warm water; it should be warm to touch, not boiling.

Take it further: Repeat the whole test with salt and see whether the order of fastest to slowest stays the same.

What it shows

When salt water is left in the sun, only the water escapes as vapour and the salt stays behind as white crystals. This is how salt pans on the coast of Gujarat and Tamil Nadu produce the salt we eat.

You will need

• 3 tablespoons salt
• 1 cup water
• A shallow steel or plastic tray, or a wide plate
• A dark cloth or black paper to put under the tray
• A sunny windowsill or balcony
• A kitchen balance, optional

Safety: Place the tray where it cannot be knocked over; keep it away from pets. No heat is needed beyond sunlight.

Take it further: Set up a second tray in the shade and compare how many days each takes to dry.

What it shows

A mixture keeps the properties of each part, so each part can be removed by a method that suits it: a magnet for iron, dissolving for salt, filtering for sand and evaporation to get the salt back. The project shows four separation methods in one go.

You will need

• 2 spoons each of clean sand, table salt and iron filings (or steel wool rubbed on sandpaper)
• A fridge magnet wrapped in a plastic bag
• A cup of water
• A funnel and a coffee filter or clean cotton cloth
• Three bowls and a shallow plate
• A kitchen balance, optional

Safety: Iron filings are sharp and must not go near eyes; an adult must make them from steel wool if needed. Wash hands afterwards.

Take it further: Add sawdust to the mixture and work out an extra step (floating on water) to remove it.

What it shows

Baking soda and vinegar react to make carbon dioxide gas, which inflates a balloon fitted over the bottle. Using more baking soda makes a bigger balloon, until the vinegar is used up and extra baking soda does nothing.

You will need

• Baking soda, 4 teaspoons
• Vinegar, 1 cup
• Four small plastic bottles of the same size
• Four balloons
• A funnel made from paper
• A measuring tape or string to measure the balloon
• Teaspoon

Safety: Do the activity on a tray; vinegar stings eyes, so do not rub eyes until hands are washed. The balloon only inflates and will not burst.

Take it further: Keep the baking soda fixed and change the amount of vinegar instead, and find the pair that gives the biggest balloon.

What it shows

A message written in baking soda water dries invisible, but a wash of turmeric water or purple grape juice turns the writing a different colour because baking soda is a base and these juices are indicators. No heat or flame is needed.

You will need

• 2 teaspoons baking soda in 4 teaspoons water
• A cotton bud or a thin paintbrush
• White paper, 3 sheets
• Turmeric water (a pinch of turmeric in 2 spoons water) or dark grape juice
• A sponge or a wide brush
• Newspaper to protect the table

Safety: Turmeric stains, so wear old clothes and work over newspaper. Nothing is tasted once used as ink.

Take it further: Reverse the trick: paint a sheet with turmeric water first, let it dry, then write with baking soda solution to get instant red writing.

What it shows

Lemon juice dries clear on paper, but gentle heat from a clothes iron turns the written lines brown before the rest of the paper changes. The acid in the juice weakens the paper fibres, so they scorch at a lower temperature than clean paper.

You will need

• Juice of one lemon in a small bowl
• A cotton bud or a matchstick without its head
• White paper, 3 sheets
• A clothes iron on a low setting (adult only)
• An old towel to iron on
• Milk or diluted vinegar for comparison, optional

Safety: An adult must operate the iron and keep it on a low setting; the child never touches the hot plate. No candle or open flame is used.

Take it further: Dilute the lemon juice with equal water and then with three parts water, and find the weakest juice that still gives a readable message.