how does lead shield from x-rays?
147339
because of the density of the atoms in lead the xrays cannot penetrate the substance.
10751
Metal detectors look for the ability of metal to conduct an induced current.  A single atom cannot have an induced current on that scale.  You need a continuous loop of ground-state metal (not the ions in our blood) to get an induced current.
396821
high velocity copper covered lead
393218
They emit radiation before being burnt, too.  They're made with a thorium alloy, and thorium is a weak alpha ray emitter similar to uranium.  I'm not sure if newer ones are made this way, but they were made with thorium for decades.
151737
some radioactive form of light can penetrate,e.g. X-rays
467769
This is an important question - the health effects of microwaves.  Some comments: Lead is not necessary.  Lead stops ionizing radiation like x-rays, but for reflecting microwaves, any conductive metal will do; aluminum is the most commonly used for microwaves, and is a better conductor than lead.\n   Metal mesh will work, just like in a microwave oven, but the problem is, it will only be really effective if you build a sealed box.  If you only cover the windows, the microwaves will come through the walls, floors and ceiling.  Also, at the joints between sheets of metal mesh, you need to have a continuous eletrical connection.  Any seam which is unconnected over a few inches will allow power in.  A large seam may behave just as if the mesh is not there at all.  (This is why a cell phone will sometimes work in an elevator, and sometimes not)  \n    I would think that using aluminum adhesive tape running down the seams of the mesh on both sides would work. \n    Anything that only covers one wall or less may help, but it may not help at all, as microwaves bend around the edges of shields, and also are reflecting off all the other parts of your building.  Any non-sealed metal mesh structure will interact with the radiation field as a open metal resonator in a very complicated way, which is hard to predict and depends on the specifics of the metal geometry, the direction and frequency of the radiation, and all the collection of reflectors in your building (pipes, wiring, window screens, reinforcing bars in concrete).  However, if the metal mesh box is truly sealed and has no open seams whatsoever, you are 100% safe.  People build these out of mesh for low-noise testing chambers, but they are hard to build, especially around doors and inlets for electrical wires and plumbing.  It really is a huge undertaking for a non-professional, sorry.\n     One final comment: you can take some comfort in the fact that if what you see outside your window are dishes, they are highly directional antennas.  Typically, they direct nearly all of their power in a cone within 1 to 4 degrees angle of the satellite or receiver where they are aimed.  Typically, stray radiation (called sidelobes) are 30 dB lower, meaning that the power radiated in other directions is one thousand times lower.  \n      Cell phone towers, however, which do not look like dishes, but an array of typically three or more panels, are not directional, and spray alot of microwave power in all directions.\n     Is there a health risk?  I'm director of a microwave engineering firm, and I don't know the answer for sure.  Just not enough data.  In my own laboratory, however, I always take all precautions to make sure no one is ever exposed to any microwave radiation, just in case.  There are national standards which govern the equipment outside your window, which do specify a maximum 'collateral' radiation level, which is deemed to be safe, based on what data does exist.  I would tend to believe that it is extremely likely they are correct about these levels being safe (safe meaning less likely to hurt you than the air pollution you breathe, the chemicals in the products you use, etc.), but we cannot be 100% sure.\n    Personally, I would be fine with living in an apartment looking out on a bunch of dish antennas, but if it was directly adjacent to a cell phone tower or building with cell phone array on it, I would not want to expose my family to it, and would move out.
75318
It's one of the densest metals, yet non-radioactive and inexpensive  - compared with its other cousins eg. Gold. Because it is so dense and heavy, can protect us from X rays and radioactive substances. It is also malleable and was used in lead pipes which gave everyone lead poisoning.
145922
The main difference between x ray and Gamma ray is that X rays originate from the electron transitions in the atom out side the nucleolus. But Gamma rays are emitted from the nucleus. \n\nX ray\nWavelength : 10 - 0.1 Angstroms (1 Angstroms = 10^-10m)\nX rays are high frequency electromagnetic rays which are produced when the electrons are suddenly decelerated - these rays are called bremsstrahlung radiation, or "braking radiation". X-rays are also produced when electrons make transitions between lower atomic energy levels in heavy elements. X-rays produced in this way have definite energies just like other line spectra from atomic electrons. They are called characteristic x-rays since they have energies determined by the atomic energy levels.\n\nWithin a short time of their discovery, they were being used in medical facilities to image broken bones. Also they are used to study the crystal structures.\n\nGamma Ray\nWavelength :  <0.1 Angstroms\nThe term gamma ray is used to denote electromagnetic radiation from the nucleus as a part of a radioactive process. The energy of nuclear radiation is extremely high because such radiation is born in the intense conflict between the nuclear strong force and the electromagnetic force, the two strongest basic forces. The gamma ray photon may in fact be identical to an x-ray, since both are electromagnetic rays; the terms x-ray and gamma rays are statements about origin rather than implying different kinds of radiation. Also they are produced from the positron-electron annihilation in presence of a nucleus.\nUsed in the gamma ray spectrometry.\n\nGamma ray autoradiography etc.\n\ni think your doubt has been clear.
664263
Cause the MRI is the best Equipment in medical imaging to have high contrast images to soft tissues\n\nand these images cant be done by Xray and CT cause X ray beam have very high attenuation to bones .... the used more in image the skull and bone structures
281802
It can only go through very thin films. Light is very high freq. X-rays are used to find small holes in welds since they go through small places well, but not metal. The fact that they conduct electricity means the magnetic part will induce a current, which creates another wave (reflection).  I have heard there is enough light passing through plywood, you can look through with an amplifier, starlight scope, night vision.
816237
I do not think that atoms will fly over the gap between a piece of gold and and old lead pipe.\n\nHowever, gold and lead readily form a wide range of alloy compositions. Lead has a high affinity for gold and can be used as a collector for gold in pyrometallurgical processes. The lead can be subsequently separated by volatilization.
222493
The problem with radiation is that it is cumulative and deadly. Dosage depends on what type of radiation it is. \nThere are 3 types: alpha, beta, and Gamma rays.\n\n\nalpha are stopped by a thin sheet of aluminum foil. Beta are stronger again, and gamma with need several feet of lead shielding. \n\nIt is the beta and gamma radiation that will pass through the human body and do damage, genetically altering cells, and resulting in tumours and genetic (mutagenic) birth defects. \n\nThe best way to deal with radio active substances is to reduce the time exposed to them, use shielding (ie a radiation suit or keep materials in a lead case etc) and distance, that is get as far from the source as possible.\n\nThey need to be transported and handled carefully, and properly labelled, and to be treated with respect.
1014547
x-rays\ngamma radiation\nnegative contrast substances (e.g. barium sulfate - opaque to X-rays)\npositive contrast media,e.g. iodine based\nTomography (http://en.wikipedia.org/wiki/Tomography)
286871
Actually, x-rays films are also very senstive to light. Light is what is actually used to expose the film to the image. \nIf an x-ray film was only senstive to x-rays they a patient would require a very high dose of radiation in order to produce an image (this is how it was done in the 1950's).\nToday we have these deveices called Intensifying Screens. The x-rays hit the intensifying screens and then give off light to make the image on the film (this helps to decrease the dose of radiation that that patient will be exposed to because the screens take each xray photon and multiple it by a lot.)\n\nAnd now to how x-ray film is developed.\n1963 to 1993 \n\nIn 1963 when I was first introduced to the X-ray business, film processors were really in their infancy. When I talk about "X-ray film processors", I mean those devices that were automated in some fashion, and the processing of film was taken out of the hands of the X-ray technician. \n\nThe first Hospital that I walked into with the man that was assigned to train me, had probably one of the first X-ray film processors in the St. Paul, Minneapolis, Minnesota area. It was a Kodak M1 or M2 processor. It was more than 8 feet long, and took 10 to 15 minutes to process a film from "dry to dry". The roller racks in the processor were so large that a "traveling" crane was attached to the ceiling to lift the racks out of the processing fluid tanks. The crane was designed to move up and down the line of travel in order to lift one or another of the racks out of the tanks. It could then be moved to lower the rack at the side of the processor where the rack could be cleaned. These roller racks allowed the film to travel in a somewhat vertical fashion, down and up, through the chemistries. The film would be fed into the rack and follow a "turn-around" which would direct the film down into the bath, traveling through the rollers. Than the film would be directed through a turn around at the bottom of the rack and brought back up to be sent over to the next rack. This was the beginning of automated film processing. I would say that the Kodak company was the father of the automated processor. There could have been others that were there 1st, but I didn't know about them. \n\nOther companies came on line soon after, but Kodak (I think) still dominates the market with its processor line. \n\nI think a step back in time, is in order to look at what the X-ray technician had to do before the automated processor became popular. \n\nThe dark room consisted of 2 or 3 tanks that were filled with chemistry. The tanks were than contained in a massive tank filled with tempered water. The water was constantly circulating and replaced as it drained out, at a controlled temperature, usually 68 degrees F. This arrangement kept the chemistry at the required temperature, so that the films could come out with very little variation in density, contrast, fog, (Etc.). The tanks were arranged so that the developer chemistry was at one end, with a "Stop" bath (sometimes) next, than the fixer chemistry, and sometimes a tank was used for the wash bath. Fixer chemistries were later changed to contain the "stop" action needed to stop development. This did away with the stop bath portion of the system. Usually the wash was done in the master water tank where the circulating water would aid in washing the film. \n\nIn this system, the film in a special holder, would be placed in the developer tank for a specified time (5 minutes more or less). Than the film was moved to the stop bath, if the system used one, or moved into the fixer tank for 10 or more minutes. Then the film was moved into the wash where it could be left for up to 20 minutes. After that the film was moved into a tall heated drying rack which looked like a large clothes locker. Depending on temperature the film would be dry in 15 to 20 minutes. \n\nCan you imagine? Some thing had to be done
659992
Alpha rays are helium nuclei (particles). Very heavy and highly charged. They are shielded by even a piece of paper.\n\nBetas are electrons (again particles). Less massive than alpha and a little more penetrating. Multiple layers of outer skin will stop these.\n\nGammas are packets of energy (radiation not particles). They can range greatly in energy and have no charge, so they are the most penetrating. That is why they are considered a whole body radiation dose. (think x-rays)
1079138
no. one xray isnt enough to harm you really, but if you were an X ray tech or something and were constantly exposed to the stuff and didnt take any preventative measures, then it may be a concern.
937524
Please don't try to feed a voltage into the patients -- most of them won't like being electrocuted!\n\nYour best hope would be to try and monitor the capacitance between the lead and the patient.  This would allow a passive (no voltage into the patients) monitoring system.\n\nBut you'll have to find out the biomechanics of this on your own...