Gravity
Watch an apple fall, change the pull of gravity, and prove you understand by controlling the drop.
Friction
Give a block the same push on different surfaces and prove that friction is what steals the motion.
Projectiles
Aim a shot, change the angle, and prove you can read the arc from the launch.
Momentum
Crash one mass into another and prove that motion is shared, not lost.
Waves
Change the pulse rate and prove that frequency packs the ripples closer.
Electricity
Change voltage or resistance and prove that current — what the lamp feels — is V divided by R.
Orbits
Change the launch speed and prove that an orbit is a fall that keeps missing the ground.
Reactions
Warm the flask or feed it more reactant and prove that rate is how fast product appears.
Ecosystems
Nudge foxes or rabbits and prove that a food web moves as one piece.
Diffusion
Warm the rooms or open the door and prove that mixing is particles wandering, not a pump.
Population
Change the growth rate or the ceiling and prove that a population is a rate meeting a limit.
Buoyancy
Change how dense the object is and prove that it floats only when the water is denser.
Springs
Stiffen the spring or change the mass and prove that a tighter coil bounces faster.
Magnets
Change the gap or the strength and prove that magnetic pull grows fast as the magnets close in.
Acids
Change pH and prove that acids turn the indicator one way and bases the other.
States
Change temperature and prove that the same substance can be ice, water, or steam.
Solubility
Warm the water or stir harder and prove that more solid can disappear into the liquid.
Gases
Change pressure and prove that a trapped gas shrinks when you squeeze it.
Equilibrium
Warm the mix and prove that a reversible reaction can lean toward products or back toward reactants.
Catalysis
Add catalyst or warm the flask and prove that a helper can hurry a reaction without being the reactant.
Electrolysis
Raise the voltage and prove that electricity can split water into bubbles of gas.
Conservation
Move mass from start to product and prove that the total does not change.
Photosynthesis
Change light or carbon dioxide and prove that a leaf builds sugar from both.
Osmosis
Change the salt outside and prove that water moves toward the saltier side.
Enzymes
Change temperature and prove that an enzyme works best near body heat and fails when it is too hot.
Selection
Change how sooty the bark is and prove that the moths that match the tree are the ones that remain.
Respiration
Change oxygen and prove that a cell needs O₂ to burn sugar for energy.
Mitosis
Change how many rounds of splitting happen and prove that one cell becomes two, then four, then more.
Immunity
Raise antibodies and prove that more defenders clear more germs.
Genetics
Change how common the dominant allele is and prove that the visible trait can show up even when it is not the only gene in the tray.