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White Light & Colour

CONCEPTUAL
Science›Waves, Light & Sound|Ages 11—12|ID: mt_qzGADV-NGe

Explain that white light is a mixture of all visible colours (ROYGBIV), describe dispersion through a prism, explain why objects appear coloured (selective reflection and absorption of wavelengths), and describe colour mixing with filters

Mastery Evidence

  • Lists the colours of the visible spectrum in order of increasing frequency
  • Explains why a prism disperses white light into a spectrum
  • Explains why a red object looks red under white light but black under blue light
  • Predicts the colour of an object seen through a colour filter

Assessment Prompt

“If [child] shone white light through a prism, could they explain why a rainbow of colours appears — and then predict what colour a blue jumper would look under red light and why?”

Curriculum Standards1 alignment

KS3.Sci.Phys.Waves.5The national curriculum in England
Visible Light and the Spectrum

visible light and the seven colours of the spectrum; white light dispersed into a spectrum of colours; light travelling in straight lines; the formation of shadows; ray diagrams

Science · KS3

Prerequisites2

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  • How We See Objects soft

    Prior work on how light reflects into the eye provides context for understanding colour perception

  • Reflection & Refraction hard

    Dispersion of white light into a spectrum relies on understanding refraction (light bending at a boundary)

    • Drawing Ray Diagrams hard

      The law of reflection is described and verified using ray diagrams for reflection

      • Measuring angles hard

        Drawing ray diagrams requires measuring angles accurately with a protractor — the core skill in mt_4MFUAsbx_6

        • Types of angles (age 8+) hard

          Measuring and drawing angles with a protractor requires knowing how to mark and label angles using standard notation

        • Degrees and turns hard

          Using a protractor requires understanding degree measurement

          • What Is an Angle? hard

            Degree measurement system requires understanding what an angle is

            • Types of angles hard

              Angle definition builds on understanding right angles

              • Right Angles & Turns hard

                Identifying right angles and greater/less than right angle is prerequisite to naming acute/obtuse

                • Understanding angles hard

                  Identifying right angles requires understanding what an angle is

                  • 2-D shapes (age 6+) soft

                    Understanding angles as shape properties requires knowing basic shape properties

                    • Angles in triangles (age 6+) soft

                      Understanding defining attributes supports describing shape properties formally

                      • 2-D shapes hard

                        Distinguishing defining vs non-defining attributes requires knowing common 2-D shape names first

                      • 3-D shapes (age 5+) hard

                        Identifying defining attributes builds on informal analysis and comparison of shapes

                    • 2-D shapes hard

                      Describing properties of 2-D shapes (sides, symmetry) requires knowing the shapes first

                    • 3-D shapes (age 5+) hard

                      Formal property description extends informal analysis of sides and vertices

                      • 2-D shapes hard

                        Analysing and comparing shapes requires being able to name them first

                      • 3-D shapes hard

                        Analysing 3-D shapes requires recognising and naming them

                  • Position, direction, and movement hard

                    Recognising angles as turns extends Y2 work on quarter/half/three-quarter turns

                    • Positional Language hard

                      Position/direction vocabulary with right angles extends basic positional language

                    • Turns & Directions hard

                      Right-angle turns (clockwise/anti-clockwise) build directly on whole/half/quarter turns from Year 1

                      • What Is a Half? soft

                        Understanding half and quarter turns benefits from the concept of halves and quarters

                      • Positional Language hard

                        Describing movement and turns builds on positional language

                • Types of angles (age 8+) soft

                  Identifying right angles and turns is supported by the convention of marking right angles with a small square

                • Position, direction, and movement hard

                  Right angles as quarter turns extends Y2 turn vocabulary

                  • Positional Language hard

                    Position/direction vocabulary with right angles extends basic positional language

                  • Turns & Directions hard

                    Right-angle turns (clockwise/anti-clockwise) build directly on whole/half/quarter turns from Year 1

                    • What Is a Half? soft

                      Understanding half and quarter turns benefits from the concept of halves and quarters

                    • Positional Language hard

                      Describing movement and turns builds on positional language

            • Right Angles & Turns hard

              Angle definition builds on classifying acute/obtuse angles

              • Understanding angles hard

                Identifying right angles requires understanding what an angle is

                • 2-D shapes (age 6+) soft

                  Understanding angles as shape properties requires knowing basic shape properties

                  • Angles in triangles (age 6+) soft

                    Understanding defining attributes supports describing shape properties formally

                    • 2-D shapes hard

                      Distinguishing defining vs non-defining attributes requires knowing common 2-D shape names first

                    • 3-D shapes (age 5+) hard

                      Identifying defining attributes builds on informal analysis and comparison of shapes

                      • 2-D shapes hard

                        Analysing and comparing shapes requires being able to name them first

                      • 3-D shapes hard

                        Analysing 3-D shapes requires recognising and naming them

                  • 2-D shapes hard

                    Describing properties of 2-D shapes (sides, symmetry) requires knowing the shapes first

                  • 3-D shapes (age 5+) hard

                    Formal property description extends informal analysis of sides and vertices

                    • 2-D shapes hard

                      Analysing and comparing shapes requires being able to name them first

                    • 3-D shapes hard

                      Analysing 3-D shapes requires recognising and naming them

                • Position, direction, and movement hard

                  Recognising angles as turns extends Y2 work on quarter/half/three-quarter turns

                  • Positional Language hard

                    Position/direction vocabulary with right angles extends basic positional language

                  • Turns & Directions hard

                    Right-angle turns (clockwise/anti-clockwise) build directly on whole/half/quarter turns from Year 1

                    • What Is a Half? soft

                      Understanding half and quarter turns benefits from the concept of halves and quarters

                    • Positional Language hard

                      Describing movement and turns builds on positional language

              • Types of angles (age 8+) soft

                Identifying right angles and turns is supported by the convention of marking right angles with a small square

              • Position, direction, and movement hard

                Right angles as quarter turns extends Y2 turn vocabulary

    • Reflecting Light soft

      Earlier work on light reflecting from surfaces provides the experiential grounding for formal reflection laws

    • Light Travels in Straight Lines hard

      Reflection and refraction build directly on understanding that light travels in straight lines and casts shadows

    • Wave Behaviour Vocabulary hard

      Applying the law of reflection and refraction requires both 'angle of incidence/reflection' and 'refraction' vocabulary

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