1029 science project ideas, from class 1 to college.

What it shows

Heat flows from hot things to cooler surroundings. Materials like thermocol, cloth and air pockets slow this flow and are called insulators, while metal lets heat through quickly. A lid matters because much heat escapes with rising warm air and steam.

You will need

• Four cups of similar size: steel, glass, ceramic (kulhad or china) and a thermocol or paper cup
• Hot water from a kettle, handled by an adult
• A thermometer
• A measuring cup
• Cardboard squares as lids
• A clock and a notebook

Safety: An adult must pour the hot water. Use water from a kettle that has been allowed to cool a little, not boiling, and keep the cups away from the table edge.

Take it further: Design and build the best insulated cup you can from waste materials and test it against a shop-bought flask.

What it shows

Liquids expand when heated and shrink when cooled. Coloured water in a sealed bottle rises up a narrow straw when the bottle is warmed and falls when it is cooled, which is exactly how a liquid thermometer works.

You will need

• A small glass or plastic bottle with a tight lid (free)
• A clear drinking straw
• Water and a few drops of food colour or ink
• Modelling clay, hot glue or candle wax to seal the straw into the lid
• A card strip and a pen for the scale
• Two bowls, one with warm water and one with cold water

Safety: An adult must make the hole in the lid and use hot glue; use warm tap water only, never boiling.

Take it further: Calibrate the scale by comparing with a real thermometer at two known temperatures and marking degrees in between.

What it shows

Water squirts furthest from the lowest hole in a bottle, because the weight of all the water above it presses on it. Pressure in a liquid increases with depth, which is why dam walls are thickest at the bottom.

You will need

• A 1 or 2 litre plastic bottle (free)
• A nail or a pin to make three holes, used by an adult
• Tape to cover the holes while filling
• A jug of water and a tray or a place outdoors
• A ruler and chalk to mark where each jet lands

Safety: An adult must make the holes with a heated nail or a sharp pin. Do the experiment outdoors or on a tray.

Take it further: Make a second bottle with three holes at the same height round its sides and show that the jets are all equal, so pressure acts equally in all directions at the same depth.

What it shows

A sachet with a small air bubble just floats in a bottle of water. Squeezing the bottle raises the pressure, squashes the bubble, and the sachet becomes denser and sinks; let go and it rises. Submarines and fish control their depth the same way.

You will need

• A clear plastic bottle with a cap, 1 litre or more (free)
• A sealed ketchup or soy sauce sachet with a small air bubble inside
• Water
• A bowl to test the sachet first

Take it further: Make a diver from the cut-off top of a dropper or a pen cap weighted with a blob of clay, and tune its air bubble until it just floats.

What it shows

Pulling the arm down stores energy in the bent stick and rubber bands, and letting go turns it into the motion of the pom-pom. More bend means more stored energy and a longer flight, and the launch angle changes the distance too.

You will need

• About ten ice cream sticks (free from a kulfi stall, washed)
• Six to eight rubber bands
• A plastic spoon or a bottle cap as the cup
• Pom-poms, paper balls or balls of foil to launch
• A measuring tape and chalk

Safety: Launch only soft things like paper balls, never stones or hard objects, and never aim at a person or an animal.

Take it further: Launch a pom-pom and a heavier foil ball with the same bend and find out which goes further and why.

What it shows

When one marble rolls into a line of touching marbles, one marble shoots off the far end; roll two in and two leave. The push, or momentum, passes right through the line, as in a Newton’s cradle.

You will need

• Six to ten marbles of the same size
• A grooved wooden ruler, or two rulers taped side by side with a gap between them
• Books to prop one end of the ruler as a small ramp
• A smooth table
• A larger or heavier marble for the extension

Safety: Keep marbles away from children under five who may put them in their mouths, and pick up any that roll on the floor.

Take it further: Build a hanging Newton’s cradle from five marbles glued to threads and a cardboard frame.

What it shows

A strip of paper with two folded wings spins as it falls, because air pushing on the slanted wings makes it turn. Longer wings catch more air and slow the fall, while adding paper clips makes it fall faster. Air resistance is a real force.

You will need

• A few sheets of used paper (free)
• Scissors
• Paper clips
• A ruler
• A stopwatch or phone timer
• A chair or a staircase to drop from safely

Safety: Drop from a chair only with an adult holding it steady, and never lean over a stair railing.

Take it further: Try the same helicopter made from thin paper, thick card and a plastic sheet, and see which falls slowest.

What it shows

A parachute slows a fall because its wide canopy pushes against a lot of air. Bigger canopies take longer to fall with the same load, and a small hole in the top makes the fall steadier instead of swinging.

You will need

• Old thin plastic bags or a cut-open polythene sheet (free)
• Thread or thin string, about 4 pieces of 30 cm per parachute
• A small toy, a bottle cap of coins or a paper cup as the load
• Scissors, tape and a ruler
• A stopwatch and a safe high place like a first-floor balcony with an adult

Safety: Drop only from a balcony or stair with an adult present, never lean over a railing, and keep plastic bags away from young children.

Take it further: Keep the canopy the same and change the load, then draw a graph of fall time against the number of coins.

What it shows

Air rushing out of the balloon’s neck pushes the balloon the other way along the string. The bigger the balloon, the further it travels. This is Newton’s third law, the same rule that lifts a real rocket.

You will need

• Balloons, long ones work best
• About 5 metres of smooth string or fishing line
• A drinking straw
• Tape
• A measuring tape
• Two chairs to tie the string between

Safety: Balloon pieces are a choking hazard for very young children; keep them away from the face when the balloon is released.

Take it further: Fix two balloons to the same straw, one behind the other, and release the second only when the first is nearly empty to make a two-stage rocket.

What it shows

A marble released from high up gains speed as it rolls down, trading height (potential energy) for speed (kinetic energy). It can climb a hill or go round a loop only if it started higher than the top of that hill or loop, and friction steals a little energy all the way.

You will need

• Long strips of cardboard from old cartons, folded into U-shaped channels (free)
• A large cardboard box or a wall to tape the track to
• Marbles
• Masking tape and a stapler
• A ruler or measuring tape
• Paper cups as stands

Safety: An adult must cut the cardboard with a knife; marbles are a choking hazard for young children.

Take it further: Time the marble over a measured straight section with a phone and work out its speed for different starting heights.

What it shows

A cardboard bird with coins hidden in its wing tips balances on its beak and even wobbles back upright when pushed. Adding weight far forward and low moves the bird’s centre of gravity to just below the beak, so it cannot topple.

You will need

• Stiff cardboard from a carton (free)
• Two one-rupee coins or two washers
• Scissors, pencil and glue or tape
• Colours to decorate
• A pencil or your finger as the balancing point

Safety: Children should use safety scissors on cardboard; an adult can cut thicker card.

Take it further: Make a balancing clown from a cork and two forks, or a balancing butterfly from a sweet wrapper and two coins.

What it shows

A drawbridge is a lever hinged at one end, raised by threads that run over pulleys at the top of the gate and are wound on an axle. The model shows how a lever, pulleys and a wheel and axle work together to lift a load with a gentle turn of a handle.

You will need

• A cardboard carton for the castle and a flat card for the bridge (free)
• Two thread spools or two bottle caps as pulleys
• A pencil as the winding axle and a bottle cap as its handle
• Strong thread, about 1 metre
• Tape, glue and a paper fastener or tape hinge
• Paints or coloured paper

Safety: An adult must cut the gateway and the holes for the axle with a craft knife.

Take it further: Add a counterweight of coins on the back of the axle so the bridge balances and the handle turns with almost no effort.

What it shows

Turning a large wheel moves a small axle with greater force, so a bucket of water can be lifted with a light push on the handle. The bigger the handle circle compared with the axle, the easier the lift but the more turns needed.

You will need

• A cut-down plastic bottle or a paper cup as the well (free)
• A pencil as the axle and a large bottle cap or a cardboard circle as the wheel or handle
• Two ice cream sticks or a cardboard frame to hold the axle
• String and a small bottle cap as the bucket
• A little water and a tray
• Glue and tape

Safety: An adult must make the holes in the frame; do the water part on a tray.

Take it further: Add a ratchet made from a cardboard toothed wheel and a stick pawl so the bucket does not drop back when you let go.

What it shows

Wrapping a paper triangle round a pencil turns its sloping edge into a spiral thread, just like a screw. A screw is an inclined plane wound round a rod, which is why it goes in with little force but needs many turns.

You will need

• Coloured paper and scissors
• Two pencils
• A felt pen to colour the sloping edge
• A real screw and a bolt with a nut to compare
• A ruler
• Tape

Safety: Screw tips are sharp; handle them by the head and keep them away from young children.

Take it further: Use a car jack or a clamp to show how a screw lifts a heavy load with a light push on the handle.

What it shows

A wedge turns a push on its wide back into strong sideways pushes at its thin edge, which split material apart. Thin, long wedges split clay with less force than short, blunt ones, which is why knives and axes are sharpened.

You will need

• A block of modelling clay or soft dough
• Three cardboard or wooden wedges of the same height but different thickness, or a butter knife, a ruler and a wooden block
• A stack of coins or a cup of sand to act as a measured push
• A ruler and a notebook

Safety: Use blunt cardboard, plastic or wooden wedges only, no sharp knives, and an adult must cut any wooden wedges.

Take it further: Test the same wedges on a bar of soap and on a potato and see whether the ranking stays the same.

What it shows

Levers differ by where the fulcrum, load and effort sit. A seesaw has the fulcrum in the middle, a wheelbarrow has the load in the middle, and tongs have the effort in the middle. Three working ice cream stick levers on one board show each class and how much they help.

You will need

• A cardboard or plywood base about 40 cm by 30 cm
• Six ice cream sticks or thin wooden strips
• Three paper fasteners or small nails as hinges
• Three bottle caps as load holders and coins as loads
• Rubber bands as force meters
• Glue, tape and labels

Safety: An adult must hammer any nails and help with the paper fasteners; keep coins away from small children.

Take it further: Measure the distances from the fulcrum to the load and the effort on each lever and work out the mechanical advantage as load arm divided by effort arm.

What it shows

The back of a shiny spoon is a convex mirror and always shows a small, upright, wide view. The bowl side is a concave mirror: it shows your face upside down from far away and large and upright when very close.

You will need

• A large polished steel serving spoon
• A small plane mirror for comparison
• A pencil or a small toy to look at
• A ruler
• A sunny window or a torch

Safety: Never use a concave spoon or mirror to focus sunlight on skin or paper, and do not look at the Sun in it.

Take it further: Use a concave shaving mirror to form an image of a window on a sheet of paper held at the right distance.

What it shows

Three mirrors set in a triangle reflect light again and again, turning a few coloured beads into a symmetrical pattern of many images. It shows how reflection works and how multiple reflections multiply images.

You will need

• An old CD case or a clear plastic sheet, cut into three strips, backed with black paper or black tape to make mirrors (free)
• A chips or cardboard tube
• Coloured beads, broken bangle pieces or bits of coloured plastic
• A piece of clear plastic and a piece of butter paper for the end
• Tape, scissors and black paper

Safety: An adult must cut the plastic strips, which can have sharp edges, and check the edges are taped over; bangle pieces are sharp too.

Take it further: Replace the beads with a clear end and point the kaleidoscope at the world to make patterns from trees and buildings.

What it shows

Sunlight looks white but is a mixture of colours. Water with a mirror in it acts like a prism, bending each colour by a slightly different amount, so the reflected beam fans out into red, orange, yellow, green, blue, indigo and violet on the wall.

You will need

• A shallow bowl or a tray of water
• A small flat mirror
• A sheet of white paper or a white wall
• Direct sunlight through a window, or a torch in a dark room
• A pencil to trace the colours

Safety: Never look directly at the Sun or shine the reflected sunbeam into anyone’s eyes.

Take it further: Make a spinning colour disc with the seven colours and show that they blend back into near white when it spins.

What it shows

A pencil standing in a glass of water looks broken at the surface because light bends when it passes from water into air. Different liquids bend light by different amounts, and a coin hidden under the rim of a cup reappears when water is poured in.

You will need

• A straight pencil or a straw
• Two clear glasses
• Water and some cooking oil
• A coin and an opaque cup
• A notebook for drawings

Take it further: Shine a torch beam through a glass of water onto a wall and trace how the beam shifts when the water is added.

What it shows

A drop of water on clear plastic has a curved top, like a convex lens, and makes small print look bigger. A rounder, smaller drop magnifies more. It shows how lenses in magnifying glasses, spectacles and microscopes work.

You will need

• A clear plastic sheet, a CD case or a piece of cling film stretched over a cup (free)
• Water and a dropper or a straw
• A newspaper with small print
• A piece of wire bent into a small loop for the extension
• A ruler

Take it further: Make a microscope with a water drop over a pinhole in a card and look at an onion skin or a hair.

What it shows

A disc painted with the seven rainbow colours looks almost white when spun fast, because the eye cannot keep up and mixes the colours together. White light is a mix of all colours, which is the reverse of a prism splitting it.

You will need

• An old CD or a circle of white cardboard (free)
• Paints or sketch pens in seven colours, or coloured paper
• A pencil, a marble or a bottle cap as the spinning axle, or a string through two holes
• A ruler and a protractor to divide the circle
• Glue

Safety: Use a blunt pencil through the disc; an adult should make the holes.

Take it further: Attach the disc to a small motor or an old toy’s wheel to spin it at a steady speed and test different colour sets.

What it shows

A ruler held over the edge of a table and twanged vibrates and makes a sound. A short overhang vibrates fast and gives a high note; a long overhang vibrates slowly and gives a low note. A harder twang makes a louder sound but not a different note.

You will need

• A 30 cm plastic or wooden ruler
• A table with a firm edge
• A pencil to mark lengths
• A free tuner or sound app on a phone, if available
• A notebook

Take it further: Build a one-string instrument from a plank, a nail, a guitar string and a bottle as a bridge, and move the bridge to change the pitch.

What it shows

A wide cone gathers sound waves from a large area and funnels them into the ear, so faint sounds become louder and clearer. Used the other way round, it sends your voice in one direction like a megaphone.

You will need

• A sheet of chart paper or a flattened cardboard carton (free)
• A kitchen roll tube or a rolled card for the handle end
• Tape and scissors
• A ticking clock or a phone playing softly as the sound source
• A measuring tape

Safety: Never shout through the megaphone into someone’s ear, and keep the small end clean if it goes near the ear.

Take it further: Make a stethoscope from a funnel and a length of rubber tube and listen to a friend’s heartbeat.