Topic 5- Light And The Electromagnetic Spectrum Flashcards
What are electromagnetic waves ?
All electromagnetic waves are transverse waves that travel at the same speed (velocity) in a vacuum
How many waves can the electromagnetic spectrum be split into ?
The electromagnetic spectrum is continuous but can be split into seven types of wave.
Order the electromagnetic spectrum in highest frequency to lowest frequency ?
In order of highest frequency to lowest the seven types are:
gamma X-ray ultraviolet (UV) visible infrared microwave radio waves
How do electromagnet waves transfer energy ?
Electromagnetic waves transfer energy from a source to an observer or object.
What wave carry’s more energy then any other type of wave on the EM spectrum?
Gamma rays carry more energy than any other wave in the electromagnetic spectrum.
How do gamma rays transfer energy to our skin ?
They may transfer energy from one source to our skin if we come into contact with gamma rays
As you Kiev from gamma rays to radio waves what happen to the wavelengths and frequencies ?
As you move from gamma rays to radio waves, the wavelengths increase and the frequencies decrease.
What wave has the shortest wavelength and the highest frequency ?
Gamma rays
What wave has the longest wavelength and the lowest frequency ?
Radio waves
What wave in the EM spectrum carry’s the most amount of energy ?
Gamma rays
Why are electromagnetic waves with higher frequencies usually more dangerous ?
Because of their energy
What are the uses of gamma rays ?
medical imaging and therapy, astronomy, sterilisation and food preservation
What are the risks of Gamma rays ?
They are extremely penetrating and damaging to living tissues and cells
Why can be use gamma rays to destroy bacteria and tumours ?
Because they carry the most energy
As wavelength of a wave increases, what happens to its frequency ?
It decreases
Which type of electromagnetic wave has the lowest frequency?
Radio waves
What waves carry the second most energy of all the waves in the electromagnetic spectrum ?
X-rays carry
What type of materials do X-rays penetrate?
soft materials (like body tissue).
Why do bones absorb X-rays ?
Bones are dense materials
We can use X-rays to build a shaded image of bones and body tissue
What are the safety precautions when dealing with X-rays ?
Due to the dangerous nature of X-rays, exposure to X-rays should always be kept to a minimum.
People working with X-ray equipment should always shield themselves to prevent exposure to X-rays.
These people will place materials (metals or lead) between themselves and the X-rays.
Hat are the risks with X-rays ?
They are highly ionising (can damage body cells), even in low doses.
What are the uses of X-rays ?
Low-energy X-rays are used for medical and industrial imaging.
High-energy X-rays are used to treat cancer.
X-rays are also used for security purposes to detect weapons in airports (and other places).
Dentists often take X-ray images of a patient’s teeth. The dentist operates the X-ray machine from behind a wall. Why does the dentist take this precaution when it is the patient who receives the dose of X-ray radiation?
The patient is only exposed to X-rays for a very short period of time. The dentist, however, may be exposed many times a day and so, over time, would be exposed to a very large amount of X-ray radiation. By operating the machine remotely, the dentist reduces their exposure to X-rays.
Where is Ultraviolet light positioned on the EM spectrum ?
between X-rays and visible light
