Is this statement true?

[SnotGoblin]

I found this on another board I am a member of. I was curious if what this guys is saying correct. ( He has been known to spout off from time to time)

 

And to address your statement directly, the Beta particle is the type of radiation closest to an electron (electrons are not actually released by radiation and are therefore not considered "radioactive particles").

 

The difference is that beta particles originate in the nucleus and electrons originate outside the nucleus in an orbiting "cloud."

 

Beta radiation is slightly damaging, but only travel a few feet through the air before being captured by a positive ion. To be really damaging to humans, they must be inhaled.

 

When a Beta particle is released, it is usually accompanied by a gamma particle, which travels much further but does less damage. It does not have the energy to ionize atoms in human tissue. A gamma particle is similar to a photon and has no mass or charge (in standard physics).

 

By comparison, a proton (as I mentioned in my original post) weighs 1 AMU (atomic mass unit). A Beta particle (the closest thing to the electron you mentioned), weighs only 549 millionths of one AMU.

 

BIG difference, wouldn't ya say?

[ydoaPs]

could you give the post that prompted the one you quoted?

he is pretty much right, though

[SnotGoblin]

could you give the post that prompted the one you quoted?

he is pretty much right' date=' though[/quote']

 

 

Eh, it really don't matter. I was just curious since he is "know it all" of sorts. Well kudous to him for getting it right. (Or least being able to copy/paste correctly)

[Severian]

I take issue with the phrase "the Beta particle is the type of radiation closest to an electron". A beta particle is an electron!

 

Other than that is seems right though. It is a bit low energy inspired, so some of the statements are really only true in certain contexts, but these contexts are the ones in which you would normally be considering beta radiation, so that is fine. (For example the associated photon can be emitted together with the electron (the gamma particle he mentions) need not be soft if the source produces high energy electrons.)

[ydoaPs]

i didn't take issue with it because he said

The difference is that beta particles originate in the nucleus and electrons originate outside the nucleus in an orbiting "cloud."

 

although i don't see how he distinguishes a gamma particle from a photon.

[Severian]

It doesn't matter where it comes from; beta radiation is made of electrons and a gamma radiation is made of photons.

[SnotGoblin]

So he's right huh?

 

Well, the blind dog gets a bone every now and then too. *shurg*

 

 

Thanks for all your help!

[DQW]

No he's NOT right.

 

A beta particle is not "like" an electron - it IS an electron. Also, a gamma ray is not "like a photon" - it IS a photon.

[DQW]

Well, the blind dog gets a bone every now and then too. *shurg*

If someone was talking about things that I was clueless about, I wouldn't have the gall to call him a "blind dog".

[[Tycho?]]

No he's NOT right.

 

A beta particle is not "like" an electron - it IS an electron. Also' date=' a gamma ray is not "like a photon" - it IS a photon.[/quote']

 

Took the words out of my mouth. And arn't gamma rays heavily ionizing? They are the highest energy photons after all.

[danny8522003]

No, they wouldnt be heavily ionising because they have such a small mass and have no charge. The ability to ionise decreases through Alpha Beta Gamma.

[MetaFrizzics]

This is partly a semantics issue. Objects get renamed when we want to distinguish sub-categories of an object based upon differences in origin or history, as well as other factors. This is a legitimate way of making the amount of precision necessary to limit the scope of scientific statements.

 

If we can distinguish one electron from another via energy levels and certain conclusions about their origin based upon trusted theoretical constraints, then we can give it a special name for convenience. Flexibility is key.

[[Tycho?]]

No, they wouldnt be heavily ionising because they have such a small mass and have no charge. The ability to ionise decreases through Alpha Beta Gamma.

 

 

Ok, but can't it still ionize atoms in humans? I thought anything in the UV range and up was capable of doing that, which is why UV, X-ray and gamma rays all can cause cancer.

 

And gamma rays dont have a small mass, they have zero mass.

[ydoaPs]

if they hit you, they can cause cancer. they gamma usually passes right through you.

[danny8522003]

Well, they may cause atoms to emit other particles which will then cause ionisation, but overall they arent as effective as Alpha or Beta.

 

Gamma rays do not ionise cells inside the body so no damage is caused. Alpha particles and beta particles would ionise cells, which could lead to the formation of cancer cells.

 

I found this here.

 

Also,

Gamma rays are indirectly ionising radiation. A gamma ray passes through matter until it undergoes an interaction with an atomic particle, usually an electron. During this interaction, energy is transferred from the gamma ray to the electron, which is a directly ionising particle. As a result of this energy transfer, the electron is liberated from the atom and proceeds to ionise matter by colliding with other electrons along its path.

 

For the range of energies commonly used in radiography, the interaction between gamma rays and electrons occurs in two ways. One effect takes place where all the gamma ray's energy is transmitted to an entire atom. The gamma ray no longer exists and an electron emerges from the atom with kinetic (motion in relation to force) energy almost equal to the gamma energy. This effect is predominant at low gamma energies and is known as the photoelectric effect. The other major effect occurs when a gamma ray interacts with an atomic electron, freeing it from the atom and imparting to it only a fraction of the gamma ray's kinetic energy. A secondary gamma ray with less energy (hence lower frequency) also emerges from the interaction. This effect predominates at higher gamma energies and is known as the Compton effect.

 

In both of these effects the emergent electrons lose their kinetic energy by ionising surrounding atoms. The density of ions so generated is a measure of the energy delivered to the material by the gamma rays.

This was found here

 

I have a feeling this may have something to do with Einstein's Photoelectric Equation or hf = phi + Ke. I hope someone with greater knowledge can shed further light on this?

 

Btw, gamma rays do not have 0 mass unless they are at rest, which they never are. Therefore because they have energy they must have mass according to e=mc^2.

 

Edit: Just found this.

Edit 2: Calculated mass of a gamma photon at 1x10^20Hz to weigh 2.2x10^-22 Kg.

[swansont]

Btw' date=' gamma rays do not have 0 mass unless they are at rest, which they never are. Therefore because they have energy they must have mass according to e=mc^2.

 

Edit: Just found this.

Edit 2: Calculated mass of a gamma photon at 1x10^20Hz to weigh 2.2x10^-22 Kg.

 

Rest mass of a photon is zero, and that is what is usually meant by mass. The full equation is E² = p²c² + m²c⁴

Any object in motion has momentum, and thus kinetic energy, which is treated as a separate term in the energy equation.

[danny8522003]

Ok, i didnt realise he was talking about rest mass which indeed would be 0, although the overall mass of a photon would be what i stated if it was not at rest though right?

 

I didnt realise the full equation was that, never seen it written like that at all before. This made for interesting reading .

[swansont]

Ok' date=' i didnt realise he was talking about rest mass which indeed would be 0, although the overall mass of a photon would be what i stated if it was not at rest though right?

 

I didnt realise the full equation was that, never seen it written like that at all before. This made for interesting reading .

 

Relativistic mass is just a measure of the total energy, so you don't account for h[math]\nu[/math] separately. Since it's frame-dependent, though, it isn't as useful as rest mass under most applications.

[danny8522003]

Could you dumb that down a bit please, it's a bit early in the morning .

 

You mean because photons are never at rest, their rest mass is not useful in most applications?

[swansont]

Could you dumb that down a bit please' date=' it's a bit early in the morning .

 

You mean because photons are never at rest, their rest mass is not useful in most applications?[/quote']

 

Rest mass is useful most of the time, since it's invariant - it's the same in all inertial coordinate systems. That means we can share that information without having to also determine the conditions of the measurement.

[danny8522003]

Ah i see - thanks for the explanation