Guided virtual science experiments for Grades 6–10. Free experiments need no account.
135 experiments found
Living things carry out all the life processes; a thing that shows only one or two, like fire or a car, is not alive
Check things for the signs of life (moving, breathing, sensing, growing, reproducing, excreting and needing food) and sort them into living, once living and never alive.
Indicators change colour in acids and bases
Use red cabbage indicator to sort everyday liquids into acids, bases and neutral substances.
Current flows only around a complete, unbroken circuit; more cells push a bigger current
Connect cells, a switch and a bulb, close and open the switch, add a second cell and break a wire to see when current flows.
Like poles repel and unlike poles attract; the force gets weaker as the magnets move apart
Bring the poles of two bar magnets together in different pairs and at different distances, and find the rule for attraction and repulsion.
The Sun drives the water cycle of evaporation, condensation and precipitation
Shine a lamp on water in a covered tank with ice on the lid. Watch evaporation, condensation and rain happen in a small model of the water cycle.
A lever balances when the clockwise and anticlockwise moments are equal
Hang a load on a metre-rule lever, push down on the other side, and find every way to balance it.
Denser liquids sink below less dense liquids
Pour honey, dish soap, water and oil into a cylinder and watch them stack in layers by density.
Some solids dissolve, and water can dissolve only a limited amount
Stir salt, sugar and sand into water. Find out which ones dissolve, and how much salt water can hold.
Evaporation turns liquid water into vapour; condensation turns vapour back into liquid
Heat salt water until the water evaporates and leaves salt behind, and watch water vapour condense on a cold lid.
Filtration separates insoluble solids from liquids
Filter muddy water and salty water. Discover what filter paper can and cannot remove.
Water quality can be compared using appearance, pH and hardness tests
Compare tap, well, river and pond water by appearance, pH and hardness, using distilled water as a control.
Roots grow best in loose soil that holds some water and lets air in; too little or too much water slows them
Grow maize seedlings in clear pots of sandy, loamy and clay soil with different amounts of water, and measure the roots.
A seed contains a tiny plant (embryo) with a food store, protected by a seed coat; beans store food in two cotyledons, maize in its endosperm
Soak a bean seed and a maize grain, open them up, and label the seed coat, hilum, micropyle, cotyledons, plumule, radicle and endosperm.
A leaf has a stalk (petiole) and a flat blade (lamina) supported by a midrib and veins, with an edge (margin) and a tip (apex)
Examine a leaf with a magnifying glass and label its petiole, lamina, midrib, veins, margin and apex.
Magnets attract iron, steel, nickel and cobalt; most other materials, including most metals, are non-magnetic
Test everyday objects with a magnet, find out what they are made of, and sort them into magnetic and non-magnetic materials.
Mass is the amount of matter and stays the same everywhere; weight is the pull of gravity and changes from place to place
Weigh objects with a beam balance and a spring balance on Earth, the Moon, Mars and Jupiter, and see which reading changes.
Read a ruler from the zero mark to the nearest millimetre, and subtract the starting mark if you cannot start at zero
Measure a pencil, an eraser and a leaf to the nearest millimetre, then learn to measure correctly with a ruler whose end is worn.
Microorganisms are too small to see without a microscope; the main groups are bacteria, fungi, protozoa, algae and viruses, and some are useful while others cause disease
Look at prepared slides and microscope images of tiny living things, find out whether they are useful or harmful, and sort them into bacteria, fungi, protozoa, algae and viruses.
Leaves with a network of veins (reticulate) usually belong to plants with tap roots; leaves with parallel veins usually belong to plants with fibrous roots
Look closely at the veins in leaves from common Nepali plants, check their roots too, and sort them into reticulate and parallel venation.
The state of matter depends on how particles are arranged and how fast they move
Heat and cool water and wax, and watch how their particles are arranged and how fast they move in each state.
Each part of a flowering plant has a job: roots take in water, the stem carries it, leaves make food, flowers make seeds, and fruits protect and spread them
Label the root, stem, leaf, flower, bud and fruit on a flowering plant, and find out the job each part does.
Physical changes can be reversed; chemical changes make new substances
Heat and cool ice, wax, sugar and egg white. Find out which changes can be reversed and which make a new substance.
Read the bottom of the meniscus with your eye level with it
Read the volume of three liquids in a measuring cylinder at the bottom of the meniscus, and see why your eye must be level with it.
At a mirror, the angle of reflection equals the angle of incidence
Shine a ray of light at a plane mirror at different angles, measure the angle of reflection, and compare a mirror with a rough surface.
Heavy insoluble particles settle, so the liquid above can be poured off
Stir sand into water, let it settle, then pour off the clear water without disturbing the sand.
A magnet separates magnetic materials from non-magnetic ones
Mix sand and iron filings, then use a magnet to pull the iron out. Find out why a magnet cannot separate salt from sand.
Light travels in straight lines, so an opaque object blocks it and casts a shadow that grows as the light comes closer
Move a torch closer to and further from an object and watch its shadow on a screen grow and shrink. Try opaque, translucent and transparent objects.
Solids keep their shape, liquids flow and take the shape of their container, and gases spread out to fill any space
Test everyday materials for shape, flow and how they fill a container, then sort them into solids, liquids and gases.
Transparent materials let almost all light through, translucent materials let some through, and opaque materials let none through and cast shadows
Shine a torch through different materials, see how much light passes, and sort them into transparent, translucent and opaque.
An object sunk in water pushes aside (displaces) its own volume of water
Lower a stone, a key, a marble and a toy into water and measure how much the water rises. Use an overflow can for a stone too big for the cylinder.
Seeds need water, warmth and oxygen (air) to germinate; light is not needed until the seedling grows
Set up dishes of bean seeds with and without water, warmth, air and light, and count how many germinate each day.
Soil is a mixture of particles of different sizes and organic matter
Shake three soil samples with water and let them settle into layers of gravel, sand, silt and clay, with humus floating on top. Compare garden, river and clay soils.
Heat, stirring and smaller pieces make a solid dissolve faster
Race sugar cubes and granulated sugar in cold and hot water, stirred and unstirred, and time how long each takes to dissolve.
Simple machines (lever, pulley, wheel and axle, inclined plane, wedge, screw) make work easier by changing the size or direction of a force
Look at how everyday tools and devices work, including a dhiki and a janto, and sort them into the six types of simple machine.
Conductors let electric current flow and insulators do not; metals and graphite conduct, while plastic, rubber, glass and dry wood insulate
Put different materials into the gap in a simple circuit, see whether the bulb lights, and sort them into conductors and insulators.
Heated liquid expands, becomes less dense and rises; cooler, denser liquid sinks to take its place
Drop a purple dye crystal into a beaker of water, heat one corner, and follow the dye as the convection current carries it round.
An element has one kind of atom, a compound has different atoms chemically joined in fixed amounts, and a mixture has substances mixed but not joined
Look at particle models of everyday substances, test whether they can be separated, and sort them into elements, compounds and mixtures.
Energy flows from producers through consumers in a food chain; only about a tenth of the energy passes to each next level
Build a food chain from organisms found around a Nepali paddy field, place each at its feeding level, and follow how energy is lost at every step.
Acceleration increases with force and decreases with mass (a = F ÷ m)
Pull a trolley with different forces and loads, read its ticker tape, and discover how force and mass change its acceleration.
Rougher surfaces and heavier objects give more friction
Pull a wooden block across glass, wood, sandpaper and oiled wood with a spring balance, and find the force that just starts it moving.
Several separation methods can be combined to separate a mixture
Use dissolving, filtration and evaporation one after another to separate salt from sand and collect salt crystals.
Water travels up the stem in xylem tubes, pulled by water evaporating from the leaves
Stand celery stalks in red-dyed water, with and without leaves, in a warm sunny place and a cool shady one, and track how high the dye climbs.
A plane mirror forms an upright, same-size, laterally inverted virtual image as far behind the mirror as the object is in front
Stand a letter card in front of a mirror at different distances and find where its image is, how big it is and which way round it faces.
Average speed = total distance ÷ total time
Time a walker, a runner, a cyclist, a bus and a tortoise over measured distances and calculate their average speeds.
Plants use light energy to make glucose from carbon dioxide and water, giving off oxygen; light, carbon dioxide and temperature can each limit the rate
Shine a lamp on pondweed and count the oxygen bubbles. Change the light distance, the light colour, the carbon dioxide and the temperature to find what limits photosynthesis.
Sound is made by vibrations; frequency sets the pitch and amplitude sets the loudness
Pluck a string on a sonometer, change its length, tightness and how hard you pluck it, and watch the sound wave on an oscilloscope.
Plant and animal cells both have a nucleus, cytoplasm, cell membrane and mitochondria; only plant cells have a cell wall, chloroplasts and a large central vacuole
Label the parts of a plant cell and an animal cell, find out what each part does, and discover which parts only plant cells have.
Pulleys change the direction of a force, and more supporting strands reduce the effort needed
Lift loads with a fixed pulley, a movable pulley and a block and tackle, and compare the effort, mechanical advantage and efficiency.
Gas, a new solid or a colour change can show a chemical reaction
Mix kitchen substances and look for evidence that a new substance has formed: gas bubbles or a new solid.
Stomata are tiny pores, mostly on the underside of leaves, opened and closed by a pair of guard cells to let gases in and out and control water loss
Look at a peel from the underside of a leaf under the microscope and label the epidermal cells, guard cells, chloroplasts and open and closed stomata.
Plants lose water vapour through stomata in their leaves; it is faster in warm, bright, windy and dry conditions
Stand a leafy shoot in water under a plastic bag and measure how much water it loses in light and dark, still and windy, dry and humid air, and with its leaves greased.
Motion can be linear, circular, rotational, oscillatory or random, depending on the path an object follows
Watch the path of moving things, from a falling stone to a spinning prayer wheel and a swinging ping, and sort them by their type of motion.
Iron rusts when both water and oxygen are present; salt speeds it up and coatings prevent it
Leave iron nails in six test tubes with different conditions for several days and find out what rusting needs, and how paint and zinc protect iron.
Decomposers such as bacteria and fungi break down dead organic matter fastest when it is warm and moist; plastic is not biodegradable
Leave fruit peel, leaves, paper and plastic in sealed jars of soil, change the moisture and temperature, and measure how much decomposes over four weeks.
Organisms have adaptations, special features that help them survive in their habitat
Study the body features of plants and animals, from a yak to a lotus, and match each one to the habitat it is adapted to.
Metals are good conductors of heat; glass and wood are poor conductors (insulators)
Stand rods of copper, aluminium, iron, glass and wood in hot water with wax beads stuck along them, and watch how fast the heat travels.
The air around us presses on everything; its pressure falls as you go higher
Travel from Biratnagar to the top of Everest with a barometer, a sealed snack bag and a glass of water held up by a card, and see how air pressure changes with height.
Air is matter: it takes up space, can be compressed, exerts pressure and expands when heated
Push the plunger of a sealed syringe full of air, then warm and cool a flask with a balloon on its neck.
Atoms join to form molecules; a molecule of an element has one kind of atom, and a molecule of a compound has two or more kinds
Build ball-and-stick models of common substances, count their atoms, and sort them into single atoms, molecules of elements and molecules of compounds.
Biodegradable waste is broken down by decomposers into harmless substances; non-biodegradable waste stays in the environment for hundreds of years
Find out what happens to different kinds of waste buried in soil for three months, and sort household waste into biodegradable and non-biodegradable.
A coil carrying a current is a magnet; more turns, more current and an iron core make it stronger
Wind a coil around an iron nail, pass a current through it, and count how many paper clips it can lift as you change the turns, the current and the core.
Burning needs fuel, oxygen and heat (the fire triangle); take away any one and the fire goes out
Cover a burning candle with jars of different sizes and time how long it burns, then put the flame out by removing oxygen, heat or fuel.
Devices transform energy from one form to another; the main useful output tells us the transformation
Find out what energy goes into and comes out of everyday devices, from an electric kettle to a micro-hydro generator, and sort them by their main energy transformation.
A liquid pushes up on an object with a force (upthrust) equal to the weight of liquid it displaces; an object floats if it is less dense than the liquid
Lower objects on a spring balance into fresh water, salt water and oil. Measure the upthrust and find out why some float and some sink.
Pollen is carried to the stigma, a pollen tube carries the male gamete to the ovule, and after fertilisation the ovule becomes a seed and the ovary a fruit
Put the stages of pollination, fertilisation, seed and fruit formation and germination in the right order, and find out where in the flower each one happens.
The pH scale from 0 to 14 measures how acidic or basic a solution is
Use universal indicator to measure the pH of seven household liquids, from lemon juice to limewater, and place each on the pH scale.
A flower's stamens (anther and filament) are the male parts and its pistil (stigma, style and ovary with ovules) is the female part; petals and sepals attract and protect
Cut a flower in half, label its petals, sepals, stamens and pistil, and find out which parts are male and which are female.
A convex lens forms real, inverted images or virtual, magnified ones depending on where the object is; a concave lens always forms small, upright, virtual images
Move an object along an optical bench in front of convex and concave lenses, trace the rays, find the image, and measure the focal length.
Settling and filtering remove particles; only disinfection makes water safe from germs
Clean muddy river water step by step: let it settle, filter it, then kill the germs by boiling or with a chlorine tablet.
A spring stretches in proportion to the force on it, so its stretch can measure force
Hang standard masses on a spring to see how it stretches, then use it as a spring balance to weigh an apple, a stone and a book.
Metals are shiny, malleable, sonorous and good conductors; non-metals are usually dull, brittle and poor conductors, with a few exceptions
Test elements for shine, hammering, ringing and electrical conduction, then sort them into metals and non-metals.
Pressure applied to an enclosed liquid is passed on equally in all directions, so a big piston gets a big force
Push the small piston of a hydraulic lift and see how the pressure is passed through the oil to lift a car on the big piston.
Pressure = force ÷ area: a smaller area or a bigger force gives a bigger pressure
Stand bricks on a foam block on their flat side, their long side and their end, and see how the contact area and the force change the pressure.
Wait until the liquid column stops moving, then read the top of the column at eye level
Measure the temperature of ice water, tap water, warm water and boiling water, waiting for the thermometer to settle before you read it.
Light bends towards the normal when it slows down entering a denser medium, and away from it when it leaves
Shine a ray into a glass block and a tank of water at different angles, measure how much it bends, and find the refractive index.
Roots absorb water mainly through their root hairs, by osmosis; salty water stops absorption
Stand young plants in measuring cylinders of water sealed with oil, compare intact roots, damaged root hairs and cut-off roots, and try salty water.
In series one current flows through everything and resistances add; in parallel each branch gets the full voltage and the total resistance falls
Wire two or three bulbs in series and in parallel, compare their brightness and the current, take one bulb out, and calculate the total resistance.
Shaping a material into a hollow boat lets it push aside more water, giving enough upthrust to float
Drop a ball of plasticine into water, then shape the same plasticine into boats and load them with marbles until they sink.
Sound needs a medium; it travels fastest in solids, slower in liquids and slowest in gases, and not at all in a vacuum
Send a sound along 1 km of air, water, wood and steel, time how long it takes, and see what happens in a vacuum.
Carbon dioxide turns limewater milky
Make carbon dioxide from marble chips and acid, then bubble it, your breath and fresh air through limewater to see which turn it milky.
A force can change an object's speed, direction or shape
Give a rolling ball a push forwards, backwards or sideways, and see how a force can speed it up, slow it down, change its direction or change its shape.
Fine-grained soils with humus hold more water than sandy soils
Pour the same amount of water through sandy soil, garden loam and clay soil in funnels, and measure how much drains through each.
When one object pushes on another, the second pushes back with an equal and opposite force
Launch a balloon rocket along a string. Change the amount of air, the nozzle and the load, and compare the action and reaction forces.
Atoms are not created or destroyed in a reaction, so a balanced equation has the same number of each kind of atom on both sides
Change the numbers in front of each substance until every kind of atom is the same on both sides of the equation, watching the molecules as you go.
The number of protons decides the element; electrons fill shells 2, 8, 8; ions have unequal protons and electrons; isotopes have different numbers of neutrons
Add protons, neutrons and electrons to build atoms of the first 20 elements, arrange the electrons in shells, and make ions and isotopes.
The right instrument depends on the quantity, its size and the accuracy needed: a tape for metres, a vernier caliper for tenths of a millimetre, a screw gauge for hundredths
Decide which instrument to use for each measurement of length, mass, time and volume, thinking about the size of the quantity and the accuracy needed.
Biodiversity can be compared by sampling with quadrats; more samples find more species until the count levels off
Place 1 m quadrats in a school field, at a forest edge and on a trampled path, count the plant species, and find how many quadrats are enough.
Concave mirrors can form real or magnified virtual images; convex mirrors always form small, upright, virtual images with a wide view
Move an object in front of concave, convex and plane mirrors, trace the reflected rays, and describe each image.
Particles spread from a high concentration to a low concentration by diffusion, faster at higher temperatures
Put a drop of food colouring into still water at different temperatures and measure how far the colour spreads over time.
Density = mass ÷ volume, a property that helps identify a material
Weigh blocks and a stone on a balance, find their volume by measuring their sides or by displacement, and calculate their density.
When the diaphragm moves down, the chest gets bigger, the pressure inside falls and air flows into the lungs
Pull and push the rubber diaphragm of a bell-jar lung model, watch the balloon lungs fill and empty, and see what a hole in the chest does.
Objects keep moving at the same velocity unless a force acts on them (Newton's first law)
Run a trolley carrying a block into a stopper and watch the block keep going. Change the speed, the block's mass and whether it is strapped down.
Pressure in a liquid increases with depth and with the liquid's density (p = ρgh)
Open holes at different depths in a tall container of water and oil, and compare how hard the liquid squirts out.
A magnetic field runs from N to S around a magnet; a current in a wire makes circular field lines whose direction follows the right-hand grip rule
Map the field around a bar magnet with a plotting compass, then pass a current through a straight wire and see the circular field it makes.
The slope of a distance-time graph is velocity; the slope of a velocity-time graph is acceleration
Follow a car moving steadily, speeding up, slowing down or parked, record its position and speed each second, and plot motion graphs.
An acid and an alkali neutralise each other to form a salt and water; at the end point the pH is 7
Add dilute sodium hydroxide drop by drop to dilute hydrochloric acid with an indicator, watch the pH change, and find the exact point of neutralisation.
For a resistor at constant temperature, current is proportional to voltage: V = I × R
Measure the current through resistors and a bulb as you add cells, plot current against voltage, and find the resistance.
Water moves by osmosis through a partially permeable membrane from a dilute solution to a more concentrated one
Soak potato strips in sugar solutions of different strengths, weigh them, and find the strength at which they neither gain nor lose water.
A dicot stem has protective, storage, transport and growing tissues; xylem carries water up and phloem carries food, arranged in a ring of vascular bundles
Look at a stained cross-section of a sunflower stem and label the epidermis, cortex, phloem, cambium, xylem and pith.
Gravitational potential energy (mgh) turns into kinetic energy (½mv²); some becomes heat when there is friction
Release a trolley from different heights on smooth and rough ramps and watch its potential energy turn into kinetic energy.
Heat can travel as infrared radiation; dull black surfaces absorb and emit it well, shiny surfaces poorly
Warm a matt black can and a shiny silver can of water in the sun, then let hot water cool in each, and compare how well they absorb and give off heat.
Higher temperature and smaller pieces make reactions faster
Drop fizzy tablets into cold, room-temperature and warm water, and crush one. Time which reaction finishes first.
Living cells respire, using oxygen and giving out carbon dioxide; respiration is controlled by enzymes and depends on temperature
Use a respirometer to measure the oxygen used by germinating, dry and boiled seeds at different temperatures, and test their gas with limewater.
Physical properties such as solubility, miscibility, melting and conductivity can be used to identify and group substances
Test common laboratory substances with water, heat and a conductivity tester, and group them by how they behave.
Humans have a double circulation: the right side of the heart pumps blood to the lungs, and the left side pumps oxygen-rich blood to the body
Follow a drop of blood from the body through the four chambers of the heart, the lungs and back out to the body, checking whether it carries oxygen at each stage.
Air is a mixture: about 78% nitrogen, 21% oxygen, 1% argon and a little carbon dioxide
Trap air in a tube with damp iron wool over water, watch the water rise as the iron rusts, and compare fresh air with breathed-out air.
Metals can be arranged in order of reactivity; a more reactive metal displaces a less reactive one
Put magnesium, zinc, iron and copper in dilute acid and compare the fizzing, then see which metals can push copper and zinc out of their salt solutions.
Work done = force × distance moved in the direction of the force; power = work ÷ time
Lift boxes of different masses onto shelves at different heights, calculate the work done, and compare the power of quick and slow lifts.
Refraction at the surface makes objects under water look nearer the top than they really are; n = real depth ÷ apparent depth
Look down at a coin at the bottom of a tank of water or oil, measure how deep it seems to be, and use it to find the refractive index.
In mitosis a cell copies its chromosomes and divides into two identical cells; meiosis makes four gametes with half the chromosomes
Look at onion root-tip cells under the microscope, identify each stage of mitosis, put the stages in order, and compare mitosis with meiosis.
DNA is a double helix of two sugar-phosphate backbones joined by base pairs (A with T, G with C); a gene is a stretch of DNA that codes for a trait, and DNA is coiled into chromosomes
Label a model of DNA, from a chromosome down to the bases, discover the base-pairing rules, and see what a gene is.
Energy used (kWh) = power (kW) × time (h); the bill depends on both how powerful an appliance is and how long it runs
Run household appliances for different hours each day, read the meter, and work out the monthly units and the cost.
An electric current decomposes an electrolyte: positive ions go to the cathode, negative ions to the anode
Pass a low-voltage current through acidified water and copper(II) sulfate solution, collect the gases, and see copper plate onto an electrode.
A changing magnetic field through a coil induces a voltage; faster change and more turns give a bigger voltage
Push a magnet into a coil, hold it still and pull it out, and watch a galvanometer. Find what makes the induced voltage bigger and what reverses it.
Enzymes speed up digestion; each works fastest at an optimum temperature and pH and is denatured by high temperatures
Mix starch with the enzyme amylase at different temperatures and pH, and test samples with iodine to see how fast the starch is digested.
Fertilisers raise yields only up to a point; extra nitrogen washes into rivers and harms them, and pesticides harm useful creatures too
Decide how much fertiliser to put on a rice field, chemical or compost, whether to spray pesticide, and see the effects on the harvest, the soil and the river.
Hard water contains dissolved calcium and magnesium salts that stop soap lathering
Shake soap with soft and hard water to compare lather and scum, then soften hard water by boiling and with washing soda.
Hydrocarbons contain only carbon and hydrogen; alkanes have only single bonds, alkenes have a double bond and alkynes a triple bond
Build models of hydrocarbons, test them with bromine water, learn their uses, and sort them into alkanes, alkenes and alkynes.
Each parent passes on one allele of each gene; a dominant allele hides a recessive one, giving predictable ratios such as 3 : 1
Cross tall and short pea plants with a Punnett square, predict the offspring, and find Mendel's 3 : 1 ratio and the test cross.
Ionic bonds form when a metal transfers electrons to a non-metal; covalent bonds form when non-metal atoms share electrons
Look at which elements each compound contains, model how their electrons are transferred or shared, and sort the compounds into ionic and covalent.
An acid reacts with a base to make a salt and water
React black copper oxide with warm dilute sulfuric acid, filter off the excess, and evaporate the blue solution to grow crystals of a salt.
A motor turns electrical energy into movement; a generator turns movement into electrical energy, using the same coil and magnets
Pass a current through a coil between two magnets to make a motor, then spin the coil by hand to make a generator that lights a bulb.
Individuals better suited to their environment survive and reproduce more, so their inherited features become more common over generations
Follow a population of light and dark peppered moths over many generations on clean and soot-blackened trees, with and without birds hunting them.
Oxidation is gain of oxygen; reduction is loss of oxygen
Heat shiny copper in air until it turns black, then heat black copper oxide with carbon to get the copper back.
Renewable sources vary with the seasons; Nepal's rivers make micro-hydro powerful, while solar and wind can fill gaps
Choose solar panels, wind turbines or a micro-hydro plant for a 60-home village in Nepal's hills, and see how much energy each gives in winter, the dry spring and the monsoon.
Running water carries soil away fastest on steep, bare slopes; plant cover, mulch and terraces slow the water and hold the soil
Pour rain onto trays of soil on different slopes, bare or protected by grass, mulch or terraces, and weigh the soil washed away.
Specific heat capacity is the energy needed to raise 1 kg of a substance by 1 °C; water's is very high
Heat water, cooking oil, an aluminium block and dry sand with the same immersion heater and compare how much their temperatures rise.
Acids react with metals and carbonates and turn blue litmus red; bases turn red litmus blue
Test dilute hydrochloric acid and sodium hydroxide solution with zinc, marble chips, litmus and phenolphthalein to discover how acids and bases behave.
Greenhouse gases such as carbon dioxide let sunlight in but trap heat radiated from the ground, warming the Earth
Shine a lamp on an open jar, a covered jar and a covered jar of extra carbon dioxide, and compare how warm each gets.
The kidneys filter waste such as urea from the blood to make urine, which flows down the ureters to the bladder and leaves through the urethra
Label the kidneys, ureters, bladder, urethra and the blood vessels of a model of the human urinary system, and follow how urine is made and removed.
In a reflex arc an impulse travels from a receptor along a sensory neuron to the spinal cord, through a relay neuron to a motor neuron and an effector, without waiting for the brain
Follow a nerve impulse from touching a hot pan to pulling your hand away, and put each part of the reflex arc in order.
Wave speed = frequency × wavelength (v = f λ); the speed depends on the medium
Change the frequency of the dipper in a ripple tank, measure the wavelength, and discover that frequency × wavelength stays the same.
Light inside a denser medium is totally reflected at the surface when it meets it beyond the critical angle
Send a ray through a semicircular glass block, increase the angle until it can no longer escape, find the critical angle, and see how optical fibres trap light.
Reactions can be classified by how the reactants rearrange: A + B → AB, AB → A + B, A + BC → AC + B, and AB + CD → AD + CB
Look at the pattern of each chemical equation and sort the reactions into combination, decomposition, displacement and double displacement.
Common gases can be identified by simple tests: oxygen relights a glowing splint, hydrogen pops, carbon dioxide turns limewater milky, ammonia turns red litmus blue
Collect gases from different reactions, test each with a glowing splint, a burning splint, limewater and damp litmus, and identify it.