Live diagrams you can run at the board.

Force diagrams

A free-body diagram with a slider for each force. The resultant updates, and the body drifts if the forces are unbalanced.

Circuits

Series and parallel circuits drawn from a component list. Open a switch and see which lamps stay lit.

Wave machine

A moving transverse wave with sliders for frequency, wavelength and amplitude, and a live v = f × λ readout.

Half-life

Step one half-life at a time and plot the count falling. The curve is the average, since real decay is random.

I-V characteristics

Sweep the supply voltage and trace the curve for a resistor, a filament lamp or a diode, with live readings.

Projectile motion (A-Level)

Set the angle, speed and launch height, fire at a target, and compare the predicted range with where it lands.

Balancing equations

Step each coefficient up and down. Atom-count bars update for every element, and a badge appears when it balances.

Collision theory

Particles move in a box. Temperature and concentration sliders and a catalyst toggle change the relative rate.

Reaction profiles

Switch a catalyst pathway on, flip exothermic to endothermic, and move the activation energy.

Le Chatelier's principle

Choose a change to concentration, temperature or pressure and the seesaw tips towards reactants or products.

pH and universal indicator

Drag a pH slider from 0 to 14 and watch the indicator colour and the hydrogen-ion concentration change.

Electrolysis

The class predicts the product at each electrode, then you reveal them with the rules applied.

Punnett squares

Pick each parent's genotype and the grid and both ratios are redrawn.

Enzyme activity

Slide temperature or pH and a marker traces the rate curve up to the optimum, then down as the enzyme denatures.

Osmosis

A concentration slider runs from hypotonic to hypertonic while the cell swells or shrinks and water arrows show the net movement.

Natural selection

Play or step a population through the generations in one of five scenarios, such as peppered moths or antibiotic resistance.

Allele frequencies (A-Level)

Step through the generations beside the gene pool, for Hardy-Weinberg, selection and genetic drift.

Circle theorems

Drag points on the circumference and watch the angles update. The theorem holds under every drag.

Pythagoras' theorem

Drag the corners to resize the legs and watch the three square areas. a² + b² = c² holds exactly each time.

Transformations

Drag the centre of a rotation or an enlargement, or step the scale factor, and watch the image move.

Three-figure bearings

Drag point B and watch the bearing and the back bearing update, both measured clockwise from north.

Match the graph

Move sliders until your dashed line or quadratic sits on the target, with the equation shown as you go.

Vector addition

Drag the arrowheads of a and b. The tip-to-tail construction and the resultant update with exact components.

What changed?

Two states side by side, such as mitosis and meiosis. Reveal the second and the rows that changed are highlighted.

Real-unit graphs

Graphs in real units with sliders, such as force and extension, terminal velocity, rate of reaction and limiting factors.

Line of best fit

Drag the ends of a line to fit a scatter graph by eye, then reveal the least-squares line to compare.

Equation rearranger

Rearrange a three-quantity formula such as F = ma on screen, or pause and let the class choose the next step.

Required-practical apparatus

Labelled rigs for the practicals, such as the ripple tank, the light microscope and electrolysis of aqueous solutions.