Noadswood Science, 2011

To understand the hazards caused by some wavelengths of the electromagnetic spectrum

Friday, April 21, 2023

Complete the electromagnetic spectrum worksheet

Waves transfer energy without transferring mater, and the amount of energy transferred varies with the wave

EM radiation can be absorbed, reflected or transmitted: -◦ Absorbed – the energy of the wave is transferred to the

matter◦ Reflected – the wave bounces back◦ Transmitted – the wave passes through a substance

The different wavelengths of EM radiation interact differently with matter

Some radiations are more harmful than others – when EM radiation enters living tissue it is often harmless, but some EM radiation can cause serious problems

What effect radiation has depends on its wavelength and the size of the dose

EM radiation such as radio waves pass through soft tissue without being absorbed

EM radiation such as microwaves are absorbed and cause heating of the cells

Some EM radiation causes cancerous changes in living cells (UV radiation can cause skin cancer with some actually destroying cells (radiation sickness after a nuclear accident)

Higher frequency EM radiation is usually more dangerous – this is because the energy of an EM wave if directly proportional to its frequency

Higher frequency waves such as X-rays and gamma rays have more energy, and it is the energy of the wave which causes the damage

Some wavelengths of microwaves are absorbed by water molecules, heating them up (this could be a problem as your cells have a large amount of water in them)

Mobile phone networks use microwaves, however there is no conclusive proof if they do / do not cause problems

UV radiation can damage DNA in cells (fluorescent tubes emit UV radiation, requiring special coatings to absorb this unwanted UV radiation)

X-rays can cause mutations, leading to cancers

Radiation can cause ionisation – the energy of the wave can bash into atoms, knocking electrons off them resulting in ions (charged)

The further radiation can penetrate before hitting an atom and getting stopped, the less damage it will do along the way (less ionising it is)

Research the dangers of different wavelengths, and the precautions that must be taken

Pick one of the following areas: -◦ Sun beds and too much Sun (UV radiation)◦ Mobile phone networks (Microwaves)◦ X-rays◦ Gamma radiation from nuclear radiation, e.g. Chernobyl

disaster

Identify what dangers the radiation can cause, do the dangers have scientific basis, and what precautions should be taken to avoid harm – make a poster / movie / PowerPoint