What are they?
X-rays are a type of electromagnetic radiation that can penetrate solids and ionize gas.
Dictionary Definition :
an electromagnetic wave of high energy and very short wavelength (between ultraviolet light and gamma rays), which is able to pass through many materials opaque to light.

Are they dangerous?
X-rays are highly dangerous, when they pass through the human body they damage cells, most of which die, but some of the damaged cells mutate and divide faster, this is the start of cancer.
X-rays are a type of ionizing radiation, which means when they hit an atom, they can knock off one of the electrons to form an ion, the free electrons then bounce of other atoms to form more ions, the ions electrical charge can lead to unnatural chemical reactions inside cells. Among other things, the charge can break DNA chains. A cell with a broken strand of DNA will either die or the DNA will develop a mutation. If a lot of cells die, the body can develop various diseases. If the DNA mutates, a cell may become cancerous, and this cancer may spread. If the mutation is in a sperm or an egg cell, it may lead to birth defects. Because of all these risks, doctors use X-rays sparingly today.
Where do they come from?
X-rays are produced by some hot gases in the universe, and by the corona of our sun
X-rays are more commonly created when a photon strikes a metal target
How do we detect them?
X-rays can be detected with a special npeice of equiptment called an x-ray detector.

What can they be used for?
X-rays can be used to treat cancer, take medical images (such as skeletal x-ray scans), and pictures of far flung stars and planets via x-ray telescopes like the Chandra X-Ray Telescope below

Anything else interesting?
X-Rays were discovered by the German Scientist W.C Rontgen in 1895 , when he noticed that flourecent materials showed a faint glow, when passed near a cathode ray tube powered by an induction coil.
He called them X-rays after the letter x in maths which is often used to represent an unknown value, he named them this because he didn't know where they came from.
A week later,external image xrays+23%252C950+roentgens+wife+copy.jpg he took a clear picture of his wife's hand, with her wedding ring on

M V Laue confirmed that X-rays were a type of electromagnetic wave in 1912

Every kind of tissue lets x-rays pass through it differently
X-rays have a wavelength of about 10nm to 0.001nm
Old CRT tellys and monitors as a by product of produceing the electrons which make the screen work, which is why the back of the glass is leaded

In the table below, fill the cells with very brief notes. Use the other pages to gather the information from, and you may want to go outside of this wiki if you really can't find the information here (though I'd be surprised!).

How are they generated?
Come from Stars, Supernovas, Black Holes, and Pulsars.
Also created on earth by Natural decay, thunderstorms and nuclear explosions.
Naturally given off by stars and other objects in the universe, can be created artificially created in a Cathode Ray Tube, or CRT
Naturally by the sun, though artificial devices are available
hot thingslumenecnt things
Caused by vibration and rotation of atoms and molecules.
Can be caused artificially by devices inside remote control devices.
Artificially by a transmitter chip.
Naturally by some planets in the universe. There is a background 'noise' of microwaves throughout the night sky.
Astronomical objects
How are they detected?
Using detectors made of densley packed crystal blocks.
With image receptors such as thin films and photographic plates.
Computer technology can generate images produced by X-rays.
Cheaply using a filter, expensive UV detectors are available.
our eyes
Night Vision/Thermal goggles or cameras
Using Receivers of Geiger Tubes.
Radio Receivers
How might they be dangerous?
Can kill human beings, can cause illness because they bare radioactive.
Can damage cells and cause mutation, can cause illness due to the radiation
Yes, UV rays can kill cells, and cause skin cancer
No, yet extremely high exposure can cause blindness
Yes. Can cause heating, and can damage or kill cells.
Can cause sunburn.
Can cause cataracts, can effect parts of your body including the brain. Can heat up water, meaning they can be extremely dangerous, I mean, they can cause you to boil from inside
Prolonged exposure can lead to cancer
What are the main or most significant uses?
To kill cells
To alter the properties of semi precious stones.
To detect for elements on far away planets
Used to take pictures of teeth and bones to help doctors.
Used in X-Ray telescopes to take pictures of far away stars
Tanning beds, killing bacteria, identifying substances, finding out about far away planets, stars, and other objects in space.
Seeingdisplaying info
lighting areas
Night Vision and Thermal Cameras/Goggles
Remote controllers
Cooking in grills and toasters.
Microwave ovens
Mobile Phones
Fixed traffic speed cameras
Weather Satalites.
Sending and receiving information
Can be used to see things via echolocation.

Good work. The section on X rays is populated with good facts and it is well presented. The table is very good.
A- merit