Science

Newton's 1st Law

An object stays at rest or moves in a straight line at constant speed unless a force acts on it.

Newton's 2nd Law

F = ma (Force = mass × acceleration).

Newton's 3rd Law

For every action, there is an equal and opposite reaction.

Inertia

The resistance an object has to changing its motion; the more mass, the more inertia.

Formula for acceleration

a = F ÷ m.

Formula for force

F = m × a.

Formula for mass

m = F ÷ a.

Unit of force

Newtons (N).

Unit of acceleration

m/s².

Convert km/h to m/s

Divide by 3.6 (e.g., 72 km/h ÷ 3.6 = 20 m/s).

Convert m/s to km/h

Multiply by 3.6 (e.g., 25 m/s × 3.6 = 90 km/h).

Convert kg to tonnes

Divide by 1000 (e.g., 5000 kg ÷ 1000 = 5 tonnes).

Flat horizontal line on distance-time graph

Object is stationary.

Straight diagonal line on distance-time graph

Constant speed.

Curve getting steeper on distance-time graph

Accelerating (speeding up).

Curve getting flatter on distance-time graph

Decelerating (slowing down).

Calculate speed from a distance-time graph

Speed = change in distance ÷ change in time.

Distance

Total length travelled regardless of direction.

Displacement

How far you are from your starting point in a straight line.

Ticker timer — even dot spacing

Constant velocity.

Ticker timer — dots getting further apart

Accelerating.

Ticker timer — dots getting closer together

Decelerating.

Proton

Positive charge, found in the nucleus.

Neutron

No charge, found in the nucleus.

Electron

Negative charge, orbits the nucleus in shells.

Atomic number

Number of protons in an atom (equals number of electrons in a neutral atom).

Mass number

Total number of protons and neutrons.

Calculate neutrons

Mass number minus atomic number.

Shell 1 capacity

Holds up to 2 electrons.

Shell 2 capacity

Holds up to 8 electrons.

Shell 3 capacity

Holds up to 8 electrons.

Electron configuration of Sodium (Na, atomic number 11)

2, 8, 1.

Electron configuration of Oxygen (O, atomic number 8)

2, 6.

Ion

An atom that has gained or lost electrons, giving it a charge.

Positive ion

Atom that has lost electrons (e.g., Na⁺).

Negative ion

Atom that has gained electrons (e.g., Cl⁻).

pH scale range

0 to 14.

Acidic pH range

0 to 6 (lower = stronger acid).

Neutral pH

7.

Alkaline pH range

8 to 14 (higher = stronger base).

pH of stomach acid

1 to 2.

pH of pure water

7.

Litmus paper in acid

Turns red.

Litmus paper in alkali

Turns blue.

Neutralisation reaction word equation

Acid + Base → Salt + Water.

Ions in an acid

H⁺ ions (hydrogen ions).

Ions in a base

OH⁻ ions (hydroxide ions).

Real life example of neutralisation

Antacids neutralising stomach acid, farmers adding lime to acidic soil, toothpaste neutralising mouth acid.

Acid-carbonate reaction word equation

Acid + Carbonate → Salt + Water + Carbon Dioxide.

Evidence of acid-carbonate reaction

Fizzing or bubbling (CO₂ gas being released).

Real life example of acid-carbonate reaction

Indigestion tablets reacting with stomach acid, limestone used in building materials.

CO₂ gas test

Bubble gas through limewater — turns milky/cloudy.

Hydrogen gas test

Hold a lit splint near the gas — squeaky pop sound.

Oxygen gas test

Hold a glowing splint near the gas — splint relights.

Independent variable

The variable you change in an experiment.

Dependent variable

The variable you measure in an experiment.

Controlled variable

Everything kept the same to ensure a fair test.

Graph requirements

Title, labelled axes with units, even scale, accurately plotted points, line or best fit.

Strong scientific conclusion

States the trend, explains the science behind it, refers to specific data values.