Key term
Edexcel GCSE Physics 1PH0
Key Concepts of Physics
Motion and Forces
Topic overviewScalar and vector quantitiesExamples of vectors and scalars, and velocitySpeed, distance, time and distance-time graphsAcceleration and the equation v squared minus u squaredVelocity-time graphs and free fallMeasuring speed in the laboratory, and typical everyday speedsNewton's first law, and investigating force, mass and accelerationNewton's second and third lawsWeight, mass and gravitational field strengthReaction time, stopping distance and large decelerationsFactors affecting stopping distance and reaction timeBraking distance, speed and work done
Conservation of Energy
Waves
Topic overviewWhat waves transfer, and the evidence for itFrequency, wavelength, amplitude and periodLongitudinal and transverse wavesThe wave equationMeasuring wave speed, and what happens at a boundaryMeasuring waves in ripple tanks, strings and solidsReflection, refraction, transmission and absorption at a boundary
Light and the Electromagnetic Spectrum
Topic overviewReflection, refraction and total internal reflectionWhy objects appear colouredLenses, ray diagrams and imagesProperties of electromagnetic wavesInvestigating refraction in glass blocksThe groups of the electromagnetic spectrumThe continuous spectrum, and what our eyes can detectEmitting and absorbing thermal radiationHow radiation is generated, and why danger rises with frequencyHarmful effects of excessive exposure to radiationUses of electromagnetic radiation
Radioactivity
Topic overviewThe atom and the size of atomsIsotopes, atomic number and mass numberRelative masses and charges of subatomic particlesElectron orbits and energy levelsForming ions, and how the atomic model changedTypes of ionising radiationBackground radiation and detecting radioactivityAlpha, beta and gamma, and their penetrating powerBeta-minus and beta-plus decayEffects of decay on atomic number and mass numberBalancing nuclear equationsActivity and the becquerelHalf-life and the randomness of decayHalf-life calculationsUses of radioactivity, and how danger depends on half-lifeThe dangers of ionising radiationSafety precautions, contamination and irradiationRadiotherapy, medical tracers and PET scannersNuclear power and where nuclear energy comes fromFission of uranium-235 and the chain reactionControlling a reactor and generating electricityNuclear fusion and how it differs from fissionWhy fusion needs extreme conditions
Astronomy
Topic overviewWeight and gravitational field strength on other bodiesThe Solar System and the order of the planetsHow ideas about the Solar System and ways of observing it have changedOrbits of moons, planets, comets and satellitesGravity, orbital speed and stable orbitsThe Steady State and Big Bang theoriesEvidence for an expanding UniverseThe Doppler effect and red-shift in galaxiesThe life cycle of a star like the SunThe life cycle of stars more massive than the Sun
Energy – Forces Doing Work
Topic overviewEnergy stores and energy transfer diagramsChanging a system's energy, and measuring work doneWork done and the energy changes it causesGravitational potential and kinetic energy calculationsDissipation and wasted energyPower as the rate of energy transferThe watt, and calculating efficiency
Forces and Their Effects
Electricity and Circuits
Topic overviewThe atom, and drawing circuit diagramsSeries and parallel circuitsPotential difference and the voltmeterEnergy transferred by moving chargeCurrent, charge and measuring currentResistance and the equation V = IRResistors in series and in parallelDesigning circuits to test componentsInvestigating resistance in circuitsCurrent-potential difference graphs for componentsLight-dependent resistors and thermistorsThe heating effect of an electric currentUses of the heating effect, and the equation E = IVtPower as energy transferred per secondCalculating electrical powerEnergy transfer in domestic devices, and power ratingsDirect and alternating currentAlternating current and the UK mains supplyLive and neutral wires, earthing and fusesFuses in the live wire, mains voltages and electrical dangers
Static Electricity
Magnetism and the Motor Effect
Electromagnetic Induction
Particle Model
Topic overviewKinetic theory and differences in densityCalculating density, and investigating itChanges of state and internal energySpecific heat capacitySpecific latent heat and thermal insulationInvestigating the specific heat capacity of waterGas pressure and the motion of particlesAbsolute zero and the kelvin scaleCompressing gases, and the force a gas exertsPressure and volume of a fixed mass of gas
Light and the Electromagnetic Spectrum
- 11 subtopics
- 31 things to know
- Paper 1
What Light and the Electromagnetic Spectrum covers
Light and the Electromagnetic Spectrum is examined in Paper 1, Physics 1. It covers reflection, refraction and total internal reflection, why objects appear coloured, lenses, ray diagrams and images, properties of electromagnetic waves, investigating refraction in glass blocks, the groups of the electromagnetic spectrum, the continuous spectrum, and what our eyes can detect, emitting and absorbing thermal radiation, how radiation is generated, and why danger rises with frequency, harmful effects of excessive exposure to radiation and uses of electromagnetic radiation.
Where it is assessed
Paper 1
Physics 1: 1 hour 45 minutes, 100 marks, 50% of the GCSE.
Check the Pearson Edexcel specification ↗The 11 subtopics
Each one has its own page.
- Reflection, refraction and total internal reflectionThe law of reflection and the normal, refraction through a glass block, total internal reflection, its two conditions and the critical angle, optical fibres, and specular and diffuse reflection from mirrors, paper and wet roads.Open →
- Why objects appear colouredWhy objects look red, white or black in white light, what a colour filter transmits and absorbs, and how books, shirts and cars appear when seen through filters or lit by coloured light.Open →
- Lenses, ray diagrams and imagesFocal length and lens power, how shape affects power, the principal focus, how converging and diverging lenses refract rays, rays through the centre and the focus, and the real and virtual images each lens forms.Open →
- Properties of electromagnetic wavesElectromagnetic waves as transverse waves travelling at 3.0 × 10⁸ m/s through a vacuum, why they form one family, and the energy they transfer from source to absorber in sunlight, microwave ovens and radio aerials.Open →
- Investigating refraction in glass blocksDrawing round the block, marking the ray with crosses, measuring the angles of incidence and refraction from the normal, the variables involved, and the pattern of results.Open →
- The groups of the electromagnetic spectrumThe seven groups of the electromagnetic spectrum in order of wavelength, which groups lie at each end and between their neighbours, and the colours of the visible spectrum from red to violet.Open →
- The continuous spectrum, and what our eyes can detectWhy the spectrum is continuous, how frequency and wavelength change from radio waves to gamma rays, and the narrow band of visible light the eye detects, with infrared and ultraviolet just outside it.Open →
- Emitting and absorbing thermal radiationHow the intensity and wavelength of radiation change as a body gets hotter, infrared from everyday objects, the Sun and the Earth, and investigating emission and absorption by surfaces with a Leslie cube, a radiant heater and covered beakers.Open →
- How radiation is generated, and why danger rises with frequencyWhy danger rises with frequency across the electromagnetic spectrum, ranking groups by potential harm, radiation from changes in electrons and nuclei, atoms raised to higher energy states or ionised, sodium lamps, and the sources of X-rays and gamma rays.Open →
- Harmful effects of excessive exposure to radiationHarmful effects of excessive exposure to microwaves, infrared, ultraviolet, X-rays and gamma rays, from internal heating and skin burns to skin cancer, eye damage and cell mutation, with sunbathing, radiographers and sunglasses as examples.Open →
- Uses of electromagnetic radiationUses of radio waves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma rays, from broadcasting, satellite links, cooking and thermal imaging to optical fibres, security marking, disinfecting water, medical images, sterilising and cancer treatment.Open →
What you need to know
Answer each one before you reveal it.
Your recallNot started
Key term
Describe how electromagnetic waves transfer energy from the Sun to Earth, in a microwave oven, to a radio aerial and to skin in sunlight.
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Compare specular and diffuse reflection, explain why a wet road dazzles at night, and name two surfaces reflecting specularly.
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Explain why a blue car looks almost black under an orange street lamp.
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Describe how the outline of a glass block is used when refraction in the block is investigated.
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List the seven groups of the electromagnetic spectrum in order, starting with the longest wavelength.
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Explain what is meant by calling the electromagnetic spectrum continuous.
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State which objects emit electromagnetic radiation because of their temperature.
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Which end of the electromagnetic spectrum carries the greater risk of harm, and why?
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Describe the harmful effect on the body of excessive exposure to microwaves.
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Explain how a microwave oven cooks food.
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State the law of reflection.
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Compare the light leaving a red filter with the white light entering it.
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Define the focal length of a lens.
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State the type of wave that every electromagnetic wave is.
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State which two angles are measured when refraction in a rectangular glass block is investigated.
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List the colours of the visible spectrum in order, starting with the longest wavelength.
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State how frequency changes across the electromagnetic spectrum going from radio waves to gamma rays.
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Describe how the intensity of the radiation emitted by a body changes as the body gets hotter.
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State which group of the electromagnetic spectrum is the most dangerous to living tissue.
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Describe the harmful effect on the body of excessive exposure to infrared.
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State the use of infrared that allows information to be carried over long distances.
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A ray strikes a plane mirror at 30° to the normal. State the angle of reflection.
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State how the power of a lens depends on its focal length.
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Explain why light from a distant star reaches the Earth across empty space but the star's sound cannot.
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State the independent and dependent variables when refraction in a rectangular glass block is investigated.
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State how wavelength changes across the electromagnetic spectrum going from radio waves to gamma rays.
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Describe how the wavelengths emitted by a body change as the body gets hotter.
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Compare the potential danger of ultraviolet with that of infrared.
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Explain why sunbathing without protection carries a risk of skin cancer.
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Give three uses of visible light.
Take Light and the Electromagnetic Spectrum further
The same content, four other ways.
Commonly confused
Pairs that lose marks when they are blurred together.
Real image vs Virtual image
Real image: a picture formed where light rays actually meet, which a screen can catch. Virtual image: a picture formed where rays only appear to come from, which no screen can catch.
Specular reflection vs Diffuse reflection
Specular reflection: the bounce from a smooth surface, with parallel rays all leaving one way and a clear picture forming. Diffuse reflection: the bounce from a rough surface, with rays scattered in many directions and no clear picture.
Converging lens vs Diverging lens
Converging lens: a glass thicker in the middle that brings parallel rays to a principal focus. Diverging lens: a glass thinner in the middle that spreads parallel rays apart.
Questions from this topic
Each one with the model answer underneath.
- 1
State the law of reflection.
Model answer
The angle of incidence is equal to the angle of reflection.
- 2
State the line from which the angle of incidence and the angle of reflection at a mirror are measured.
Model answer
Both are measured from the normal, drawn at right angles to the mirror surface.
- 3
A ray strikes a plane mirror at 30° to the normal. State the angle of reflection.
Model answer
The angle of reflection is 30°, because it equals the angle of incidence.
- 4
Describe what happens to a ray of light entering a glass block at an angle to the normal.
Model answer
It refracts at the surface and bends towards the normal as it enters the glass.
- 5
Describe the path of the ray leaving a rectangular glass block, compared with the ray that entered it.
Model answer
It travels parallel to the ray that entered but is shifted sideways.
- 6
Define total internal reflection.
Model answer
Total internal reflection is when light meeting a boundary from inside the denser material is entirely reflected back and none escapes.
What is inside Levo
Six ways to work the same material.
Light and the Electromagnetic Spectrum revision questions
- What does Light and the Electromagnetic Spectrum cover in Edexcel GCSE Physics?
- 11 subtopics: reflection, refraction and total internal reflection, why objects appear coloured, lenses, ray diagrams and images, properties of electromagnetic waves, investigating refraction in glass blocks, the groups of the electromagnetic spectrum, the continuous spectrum, and what our eyes can detect, emitting and absorbing thermal radiation, how radiation is generated, and why danger rises with frequency, harmful effects of excessive exposure to radiation and uses of electromagnetic radiation. Each one has its own page with questions and model answers.
- How is Light and the Electromagnetic Spectrum organised?
- By the Edexcel 1PH0 specification, subtopic by subtopic, so it matches the order you are taught it in.
Every question in Light and the Electromagnetic Spectrum, on a schedule.
Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.
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