radiation is stopped by only 6 inches of Lead. how and why?

Answer 1

Only some radiation is stopped by 6" of lead, not all.
Radiation is blocked by something else getting in the way; it is as simple as that. The denser it is the more of it to get in the way. This is why lead makes a good form of shielding.

Radiation is a stream of subatomic particles. The components of the stream can vary and that determines the type of radiation.

Alpha radiation is very similar to the nucleus of a helium atom. It can be stopped by a piece of paper.

Beta radiation is another combination of subatomic particles and it can be stopped by a thin sheet of lead.

Gamma rays are fast moving electrons and it takes feet of lead to stop them. Some of them are so energetic that they still get through.

Anything can be radiation shielding; all it has to be is dense. If the molecules can get in the way of the radiation to absorb or block it then that substance is providing radiation shielding. Lead, concrete, and water are some of the most common forms of shielding used. Lead is denser than water or concrete and it is common. It also can be easily worked so it can be formed into a suit easier than a sheet of steel. It can be also made flexible and it can be used to line something. When done like this the lead would be denser than an equal amount of most other metals. This means it provides better radiation shielding.

Light is a form or radiation as are radio waves, radar waves and microwaves. These are all composed of photons and photons are very fast (speed of light) tiny particles that can be blocked by the thinnest substance, as long as it is opaque.

A neutrino is neutrally charged particle of radiation. It is very hard to block neutrinos. Scientists have built neutrino detectors and had to put them at the bottom of 3 mile deep mine shafts so that all that earth can slow the neutrinos down enough to be read by the detector. Gamma rays are some of the strongest and deadliest types of radiation no amount of shielding will block ALL gamma rays, you can have 3 miles of lead and some of it will still get through. However, that amount will be so microscopic that you would have a problem detecting it.

Answer 2

It's late so this is short perhaps even terse - sorry about that.

To quote a famous book title, your question is 'not even wrong' and Dan has provided numerous errors to further complicate the issue.

Try the Wiki reference below for a simple explanation of the types and properties of ionizing radiation.

Briefly, ionizing radiation is either moving particles or electromagnetic radiation which is one of the reasons your question/statement is too simple -
> alpha particles are 'radiation' (*helium* nuclei not hydrogen) and they can travel only a few inches in air (depending on their energy) so inches of lead is not necessary (not even wrong).
> beta radiation is also particulate (*electrons*, not a combination of subatomic particles) and travels only a few meters in air [again, no lead necessary]. *Also,* using high-density materials [like lead] for shielding electrons actually produces more radiation than materials like plastics.

Email if you have a need for accurate answers.

added later:
Dan S - glad to see you corrected most of your errors and added a reference after I emailed you my comments...

Answer 3

Only 6".... what you expected more? That's a foot of led, that's a lot!

Well Lead has the highest atomic number that all stable elements. That means that its molecule is HUGE. This way it can block effectively all radiation except, neutron radiation

Answer 4

If the metal Radium is left alone, after losing all radiation Lead remains.
Kimon`s answer is right.