Curriculum Portal

neurologyYou need to know

• White light is made up of a mixture of all the colours of the visible spectrum.
• The visible spectrum consists of the colours red, orange, yellow, green, blue, indigo, and violet, in that order (ROYGBIV).
• A prism splits white light into its constituent colours by refraction, a process called dispersion.
• Rainbows are formed when sunlight is refracted and dispersed as it enters water droplets in the atmosphere, internally reflected inside the droplets, and refracted again as it leaves.
• Shorter-wavelength visible light such as blue/violet is refracted more than longer-wavelength visible light such as red in glass; fibre-optic communications usually use infrared because it is transmitted with low loss, and fibres guide light by total internal reflection.
• Refraction is the bending of light as it passes from one medium to another due to a change in speed.
• The angle of incidence is the angle between the incoming ray and the normal (a line perpendicular to the surface).
• The angle of refraction is the angle between the refracted ray and the normal.
• The relationship between the angle of incidence and the angle of refraction depends on the refractive indices of the two media (Snell's Law).
• The primary colours of light are red, green, and blue.
• Reflection is when light bounces off a surface; transmission is when light passes through a material; absorption is when light is taken in by a material.
• We see coloured objects because they reflect certain colours of light and absorb others.
• Filters only transmit light of the same colour as the filter and absorb or reflect other colours.
• Light travels in straight lines called rays.
• Eyes and cameras collect light to form an image.
• The image formed by a camera or the eye is inverted (upside down) due to the way light rays are focused by a lens.
• The retina forms an inverted image, and the brain interprets patterns of neural signals from the retina to produce visual perception rather than literally flipping the image.
• The parts of a camera (lens, aperture, and sensor/film) are analogous to parts of the eye (lens, pupil, and retina).
• Visible light is a part of the wider electromagnetic spectrum.
• The electromagnetic spectrum includes, in order of increasing wavelength: gamma rays, X-rays, ultraviolet, visible light, infrared, microwaves, and radio waves.
• Different regions of the electromagnetic spectrum have different uses (e.g., X-rays for medical imaging, microwaves for cooking, and radio waves for communication).
• Lenses refract rays of light to focus them to a point.
• The shape and size of a lens affect how it refracts light and the image it forms.
• Convex lenses converge light rays to a focal point and are used to correct long-sightedness; concave lenses diverge light rays and are used to correct short-sightedness.
• The power of a lens is related to its shape (more curved lenses have greater power).

• Explain that white light is made up of all the colours of the visible spectrum and describe how a prism splits white light into its constituent colours.
• List the colours of the visible spectrum in order.
• Describe and explain the process of refraction, including how and why light bends when passing between different media.
• Analyse and predict the relationship between the angle of incidence and the angle of refraction, including using Snell's Law for calculations.
• State the primary colours of light and explain how mixing them produces secondary colours.
• Describe and distinguish between reflection, transmission, and absorption of light.
• Explain how coloured objects appear under different coloured lights, based on reflection and absorption.
• Use a ray diagram to show how light travels in straight lines and how lenses focus light to form images.
• Compare the structure and function of a camera and the human eye, identifying corresponding parts.
• Compare different regions of the electromagnetic spectrum, their order, and their uses.
• Relate the shape of a lens to its power and effect on light rays, and explain how different lenses correct vision defects.
• Use ray diagrams to demonstrate how convex and concave lenses affect the path of light rays and the images formed.