The electromagnetic spectrum (P4.2) | OCR GCSE Combined Science A (Gateway Science) — Physics — Higher (J250)

P4.2 The electromagnetic spectrum

Summary Having looked at mechanical waves, waves in the electromagnetic spectrum are now considered. This section includes the application of electromagnetic waves with a specific focus on the behaviour of light. Alongside this, it explores the application of other types of electromagnetic radiation for use in medical imaging. Underlying knowledge and understanding Learners may be familiar with the uses of some types of radiation but an understanding of all parts of the electromagnetic spectrum is not expected and should be taught as new content.

Common misconceptions Learners can have misconceptions such as gamma rays, X-rays, ultraviolet light, visible light, infrared light, microwaves and radio waves being independent entities and not being able to view it as a spectrum. They struggle to link the features that waves have in common, alongside the differences and how these relate to their different properties.

Learning outcomes	To include	Maths	Working scientifically	Practical suggestions
$P4.2a recall that electromagnetic waves are transverse and are transmitted through space where they all have the same velocity$

P4.2a recall that electromagnetic waves are transverse and are transmitted through space where they all have the same velocity

P4.2b explain that electromagnetic waves transfer energy from source to absorber

examples from a range of electromagnetic waves

P4.2c apply the relationships between frequency and wavelength across the electromagnetic spectrum

WS1.1b, WS1.3b, WS1.3e

Investigation of electromagnetic waves on chocolate or processed cheese in a microwave to measure wavelength. (PAG P4)

P4.2d describe the main groupings of the electromagnetic spectrum and that these groupings range from long to short wavelengths and from low to high frequencies

radio, microwave, infrared, visible (red to violet), ultraviolet, X-rays and gamma rays

WS1.1c, WS1.1d, WS1.1e, WS1.1f, WS1.1h, WS1.1i

Research and design a poster to show the properties, uses and dangers of the different electromagnetic wave groups.

P4.2e describe that our eyes can only detect a limited range of the electromagnetic spectrum

P4.2f recall that light is an electromagnetic wave

P4.2g give examples of some practical uses of electromagnetic waves in the radio, microwave, infrared, visible, ultraviolet, X-ray and gamma ray regions

WS1.1b, WS1.1d, WS1.1e, WS1.1f, WS1.1h, WS1.1i, WS1.3e, WS1.3f

Demonstration of how microwaves can be used to heat water in a beaker which can in turn be used to light a bulb. This will help to demonstrate that microwaves can heat water and in turn how food is heated. Use a microwave emitter and absorber to demonstrate behaviour of waves. (PAG P4) Use of a phone camera to look at the infrared emitter on a remote control. (PAG P4)

P4.2h describe how ultraviolet waves, X-rays and gamma rays can have hazardous effects, notably on human bodily tissues

WS1.1a, WS1.1c, WS1.1d, WS1.1e, WS1.1f, WS1.1h, WS1.1i

Show images of X-rays to discuss how the images are formed; their advantages and disadvantages. Investigation of the balance of risks for staff and patients during radiotherapy.

P4.2i recall that radio waves can be produced by, or can themselves induce, oscillations in electrical circuits

P4.2j recall that different substances may absorb, transmit, refract, or reflect electromagnetic waves in ways that vary with wavelength

P4.2k explain how some effects are related to differences in the velocity of electromagnetic waves in different substances

The electromagnetic spectrum

Next Steps

Learning Objectives