1029 science project ideas, from class 1 to college.

What it shows

Sunlight warms the water, some of it evaporates into vapour, the vapour cools on the plastic and condenses into droplets, and the droplets run down as "rain". The same four stages drive the real water cycle.

You will need

• A clear zip-lock bag
• A quarter cup of water
• A drop of blue food colour
• A permanent marker
• Tape
• A sunny window

Take it further: Tape a second bag on a shaded wall and compare how long the droplets take to appear.

What it shows

Clouds form when moist air expands and cools, and water vapour condenses on tiny particles. Squeezing the bottle warms and clears the air; letting go expands and cools it so a cloud appears, but only when smoke particles are present to condense on.

You will need

• A clear 1 litre plastic bottle with cap
• A little warm water, not boiling
• An incense stick or a matchstick for a wisp of smoke
• A dark background to see the cloud

Safety: An adult must light and blow out the incense stick. The water should be warm to the touch only, never hot enough to soften the bottle.

Take it further: Measure the temperature of the water each time and find the warmest water that still gives a clear cloud.

What it shows

The dew point is the temperature at which air becomes saturated and water starts to condense. Cooling a shiny can slowly until it mists over gives the dew point, and from dew point and air temperature the relative humidity can be read from a table.

You will need

• A clean shiny steel or aluminium can
• A thermometer that reads to 1 degree or better
• Ice cubes and water
• A stirring rod
• A relative humidity table printed from a textbook
• A notebook

Safety: Handle the thermometer gently; a digital probe is safer than glass.

Take it further: Build a wet-and-dry bulb hygrometer from two thermometers and compare its humidity values with the dew point method.

What it shows

Runny lava spreads far and builds wide, low shield volcanoes; thick, sticky lava piles up near the vent and builds steep cones. Pouring liquids of different viscosity through a hole in a tray shows the two shapes forming.

You will need

• A flat tray or a sheet of plastic on a table
• A paper cup with a small hole in the bottom
• Water with a drop of colour
• Cooking oil
• Honey or thick sugar syrup
• A ruler and a stopwatch

Safety: Wipe spills at once; oil and syrup on the floor are slippery.

Take it further: Warm the honey in a bowl of hot water and repeat to show how temperature changes viscosity and flow.

What it shows

The Earth's crust is broken into plates that float on the soft upper mantle. Pushing two biscuits apart, together, or sideways shows how ridges, mountains and faults form at the three kinds of plate boundary.

You will need

• Four plain rectangular biscuits
• A thick layer of jam or wet flour paste on a plate
• A glass of water
• A sheet of paper for sketches
• A marker

Safety: Wash hands before and after; the biscuits are not to be eaten after handling.

Take it further: Push one biscuit under the other to model subduction, and discuss why deep ocean trenches form there.

What it shows

Crayon shavings pressed together act like sediment turning into sedimentary rock, pressed and warmed they become metamorphic rock, and melted and cooled they become igneous rock. The same changes, with real heat and pressure over millions of years, make up the rock cycle.

You will need

• Three old wax crayons of different colours
• A pencil sharpener or a plastic knife for shaving
• Aluminium foil folded into small cups
• A bowl of hot water from a kettle
• A heavy book
• Paper towels

Safety: An adult must pour the hot water and handle the foil cup while it floats. Do not use a flame or a microwave for the wax.

Take it further: Repeat with sugar instead of wax under adult supervision and compare how the crystals look after cooling.

What it shows

A harder material scratches a softer one. Using a fingernail, a copper coin, a steel nail and a piece of glass as reference points, any rock or mineral can be placed on the Mohs hardness scale from 1 to 10.

You will need

• Rocks and minerals collected locally: chalk, brick, granite, marble chips, quartz pebbles, slate
• A copper coin or a thick copper wire
• A steel nail
• A piece of glass with taped edges
• A hand lens
• A notebook and labels

Safety: Tape the glass edges and let an adult hold it while testing. Wear old clothes; rock dust stains.

Take it further: Test a streak colour by rubbing each sample on an unglazed tile and add a streak column to the table.

What it shows

Soil is a mixture of sand, silt and clay particles of different sizes. Shaken in water, the heavy sand sinks in a minute, silt in a few hours and clay over days, so the layers in the jar show the soil's texture.

You will need

• Two or three clear jars with lids
• Soil samples from a garden, a field and a roadside
• Water
• A pinch of salt or a spoon of detergent to help clay separate
• A ruler
• A soil texture triangle from a textbook

Safety: Wash hands after handling soil.

Take it further: Grow seeds in each soil type and compare growth after two weeks.

What it shows

Water passes through soils at very different rates. Sand lets water through in seconds, clay holds it for a long time, and the result decides where groundwater forms, where floods happen and which crops grow.

You will need

• Four funnels made from cut bottle tops
• A piece of cotton cloth for each funnel
• Equal volumes of sand, garden soil, clay soil and gravel
• Four measuring cups or marked glasses
• A stopwatch
• A jug of water

Safety: An adult should cut the bottles; tape the cut edges.

Take it further: Mix sand and clay in different ratios and find the mix that drains at a medium rate.

What it shows

A vertical stick's shadow is longest at sunrise, shrinks until the Sun is highest, then grows again. The shortest shadow points true north from anywhere in India, and the time it happens is local solar noon, which is usually not 12 o'clock by the clock.

You will need

• A straight stick about 30 centimetres long
• A flat open patch of ground or a large sheet of card
• Pebbles or chalk
• A clock
• A string and a ruler
• A compass to compare

Safety: Never look straight at the Sun. Drink water and wear a cap if staying outside long.

Take it further: Repeat the same day a month later and compare the length of the noon shadow to see the Sun's changing height.

What it shows

The same beam of light spread over a larger area heats each square less. Sunlight arrives at a slant in winter and spreads thin, which is the main reason winter is cold, not the small change in distance from the Sun.

You will need

• A torch with a narrow beam
• A sheet of graph paper or a hand-drawn centimetre grid
• A protractor
• A ruler
• A dark room
• Optional: a thermometer and a black card

Take it further: Measure the noon Sun angle in your town in June and December with a shadow stick and compare it with your torch results.

What it shows

When a river reaches the sea it slows down suddenly and drops the sediment it was carrying. The sediment builds a fan of land called a delta that splits the river into many channels, which is how the Ganga-Brahmaputra and Godavari deltas formed.

You will need

• A long tray, raised at one end
• Sand and a little soil to make it muddy
• A clear plastic box at the low end filled with water as the sea
• A jug of water
• A straw to make the channel
• A ruler

Take it further: Add a little salt to the "sea" and compare how quickly the mud settles; clay clumps faster in salt water.

What it shows

Land heats and cools much faster than water. In summer the hot Indian land has low pressure and air flows in from the cooler sea, carrying moisture; in winter the land is colder and the flow reverses. Measuring sand and water under the same sun shows the difference that drives the monsoon.

You will need

• Two identical containers
• Dry sand and water to the same depth
• Two thermometers
• A sunny spot and a shaded spot
• A notebook and a clock
• Optional: a lamp for a repeat indoors

Safety: Handle glass thermometers gently; a digital probe is safer.

Take it further: Repeat with wet sand and show how moist ground behaves more like water.

What it shows

Craters on the Moon were made by rocks hitting its surface. Dropping marbles into flour from different heights shows that faster impacts make wider craters with longer rays, and that the Moon keeps its craters because it has no air, water or weather to wear them away.

You will need

• A deep tray
• Flour about 3 centimetres deep
• A thin layer of cocoa powder or coloured powder on top
• Marbles or stones of different sizes
• A metre rule
• A small ruler to measure craters

Safety: Drop, do not throw; keep faces away from the tray.

Take it further: Drop the same marble at an angle and see whether the crater is still round; real craters usually are.