Technetium-99m (1 Viewer)

[Dreamerish*~]

We have this lovely radioisotope: technetium-99m.

What exactly does the m mean? I've heard a rumour - that it means the radioisotope emits only gamma rays. However, my tutor quashed those beliefs by telling us that no radioisotope is capable of emitting only gamma rays.

Then again, he has been wrong about several things.

So I'm throwing myself on the mercy of BoS chemists. What is the mystery m?

 

[rama_v]

Well from this site:

http://www.epa.gov/radiation/radionuclides/technetium.htm

They seem to suggest that Tc-99m is the most common isotope of Technetium-99. Technetium-99 apparently has no known uses, so I would think the name of the medical isotope is Tc-99m NOT Tc-99...

Technetium-99 has a radioactive half-life of 212,000 years. Technetium-99m (called metastable Tc-99) decays to Tc-99 primarily by gamma emission, and has a half-life of only about 6 hours. Technetium-99 decays to form ruthenium-99, which is stable, by emitting beta and gamma radiation.

Also I think your teacher might be wrong about the gamma radiation thing, although I do know that the emission of an @ particle or beta particle is usually followed by the emission of a gamma ray (from physics, an accelerating charged particle emits emr).

 

[serge]

Also I think your teacher might be wrong about the gamma radiation thing, although I do know that the emission of an @ particle or beta particle is usually followed by the emission of a gamma ray (from physics, an accelerating charged particle emits emr).

rama's right, since in textbooks * denotes an excited nucleus
and ive seen these types of equations

Element*--> Element + gamma

 

[kami]

heehee, I asked this question in Chemistry and then the teacher said:
Teacher:"Do we have any students who have done Physics in our class that can help explain it"
Me:*raises hand slowly..*
Teacher: "er hmmm...I'll get back to you next week after looking it up, and you do the same and we'll see what we get"
*next week comes by*
Teacher: "So you have any answers yet?"
Me: "Ummm..."
*another week comes by*
Teacher: "Well after some long and rigorous research, I have discovered that the m stands for meta-stable"
*cue teacher's self satisfied smile as I slowly realise he was reading from our text book*
Then for the first time I actually bother to look it up and I find this which basically answered my question. Hope it answers yours.

 

[Dreamerish*~]

I've found the explanation.

It's a simple one.

M stands for medicine. It indicates that the isotope in question is used for medical purposes.

 

[kami]

I've found the explanation.

It's a simple one.

M stands for medicine. It indicates that the isotope in question is used for medical purposes.

Really?...
Both the Macquarie Study guide and wikipedia both state m = metastable. In addition, I have never seen Cobalt 60, Iodine 131 or Iodine 123 labelled with an m and they are certainly used for medical purposes..

 

[Dreamerish*~]

Really?...
Both the Macquarie Study guide and wikipedia both state m = metastable. In addition, I have never seen Cobalt 60, Iodine 131 or Iodine 123 labelled with an m and they are certainly used for medical purposes..

*Sigh*

I'm going to throw a brick at my tutor's head.

I think I'm just going to go with the "metastable" definition. Maybe I just won't bring it up at all in my answer.

 

[Haku]

*Sigh*

I'm going to throw a brick at my tutor's head.

I think I'm just going to go with the "metastable" definition. Maybe I just won't bring it up at all in my answer.

haha, yea it means metastable. but i don;t think u need to know it if u don;t do medical physics. Basically means this atom is very excited and energised. and if memory serves me right, i think it only emits gamma radiation and nothing else.

*even in medical phy u need to know it. just have to write with it