PSLE Science — Physical Science Revision (Concept Map)

PSLE Science — Final Revision

Physical Science · the topics that came up in every paper, and how they were asked

Most-tested physical topics, 2023–2025: states and the water cycle 10, electricity 8, heat 7, magnets 6, light 6, springs 5.

Light, forces and energy came up only as MCQs — the long answers landed on states, springs, magnets and heat.

Booklet A Q15–28 and Booklet B Q35–40 are Physical Science. From 2026: 30 MCQs (60 marks) + open-ended (40 marks), 1 h 45 min.

States & the Water Cycle (10)

Heat in, heat outMelting, boiling and evaporation gain heat; condensation and freezing lose it. Temperature holds during the change.

Boiling, evaporation and dewBoiling: bubbles form throughout at a fixed temperature. Evaporation: surface only, any temperature. Dew: vapour condensing on a cold surface.

Electricity (8)

A closed circuitBattery, wires, bulb, switch — an open switch breaks the circuit and the bulb goes out.

BrightnessMore batteries or fewer bulbs in the loop makes the bulb brighter; identical bulbs share the current.

Why a bulb blowsToo much current: too many batteries, or too few bulbs, in the circuit.

Heat (7)

Conduction and insulationHeat travels through solids, particle to particle, best in metals; a double wall with air between slows it down.

ExpansionHeating expands, cooling contracts — a hot wheel shrinks to fit the rim; a heated wire lengthens.

Magnets & Electromagnets (6)

PolesLike poles repel, unlike poles attract; the force acts at a distance, strongest at the poles.

What they attractIron and steel only. Steel bars attract each other only where they are magnetised.

ElectromagnetA current in a coil around an iron bar makes a magnet that switches off with the current.

Light & Shadow (6)

Shadow sizeLight travels in straight lines; move the object or the light closer to the screen and the shadow grows.

How much light passesTransparent almost all (a diamond or jelly is seen clearly), translucent some, opaque none.

Springs & Elastic Force (5)

Stretch and pushA spring stretches when pulled and pushes back when squeezed; it stores elastic potential energy.

Using springsThe greater the stretch or squeeze, the greater the force — springs launch, hold and cushion.

Matter, Floating & Measuring (7)

Properties decide the materialStrength, flexibility, waterproofing and transparency — choose the material that suits the job.

Floating and measuringFind a floating object's volume by displacement; read a tape or ruler from the correct mark.

Forces & Energy (8)

Gravity and frictionGravity pulls things down; friction opposes movement — helpful for grip and braking, harmful as wear.

Energy conversionsLamp: electrical to light + heat. Spring: elastic to kinetic. Some energy always escapes as heat.