Period: 2 By: Mozzel Rodriguez


Electromagnetic waves are waves which can travel through the vacuum of outer space. Mechanical waves, unlike electromagnetic waves, require the presence of a material medium in order to transport their energy from one location to another. X-rays are a type of electromagnetic waves.

An electromagnetic wave of high energy and a very short wavelength, which is able to pass through many materials opaque to light. X-rays are very high frequency waves, and carry a lot of energy. The fact that they pass through most substances makes them useful in medicine and industry to see inside things. X-rays are given off by stars, and strongly by some types of nebula. An x-ray machine works by firing a beam of electrons at a "target". If we fire the electrons with enough energy, x-rays will be produced.

Everyday Applications

One of the most familiar X-ray machines is the baggage scanner found at airport terminals. This low-power X-ray device is placed over a conveyor belt, where it scans passengers' luggage. The machine used in this type of scanner must operate at a very specific frequency. It must be high enough to penetrate hard-shell baggage but low enough to prevent the accidental exposure of camera film.

Another common application is in the form of X-ray machines, which take photos of a patient’s body. If an arm or leg were broken for example, then this limb would be put in front of the X-ray with a piece of photographic film behind. The X –ray is turned on briefly and goes through to the film. The rays go through the skin and flesh easily, showing up as dark areas on the film, but with more difficulty through bone. They are slowed down and so these areas are much lighter. X-rays can also be used to kill cancer cells, but also kill healthy cells, so must be used with much care.

Health Impacts

The benefits and advantages of X-rays compared to other types of imaging include that they are fast — the results of X-rays are often available the same day, in simple cases even within the hour, they are painless and non-invasive, they don’t require any special preparation (except when contrast media is used) and they require no recovery time — you can go straight back to work or school after an X-ray is finished.

Ionizing radiation can cause cell damage. Being exposed to significant amounts of radiation from X-rays and CT scans may increase your risk of developing cancer a decade or more into the future. However, this risk is low and needs to be weighed up against the benefits. Different scans involve different amounts of radiation. With a very low dose X-ray, such as a single chest X-ray, the dose of radiation is roughly the same as you would receive from the general environment over about a week, or from taking a long-distance, international plane flight.

How X-rays see through your skin - Ge Wang