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Topic: heavy metal?  (Read 16297 times)

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Offline Polleke

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heavy metal?
« on: January 02, 2010, 12:45:17 PM »
Dear all,

how would you define a heavy metal?

We all speak of heavy metals, but how would you define it ? Or better: what definition would you pick of someone asks you what a heavy metal is?

Offline Schrödinger

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Re: heavy metal?
« Reply #1 on: January 02, 2010, 01:23:40 PM »
There is no clear drfinition as such.
See http://en.wikipedia.org/wiki/Heavy_metal_%28chemistry%29
"Destiny is not a matter of chance; but a matter of choice. It is not a thing to be waited for; it is a thing to be achieved."
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Offline bromidewind

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Re: heavy metal?
« Reply #2 on: January 02, 2010, 11:10:41 PM »
None of the international naming conventions have a concrete definition for "heavy metal", which has resulted in inconsistency in scientific literature, something that needs to be remedied. I found an article about the definition of heavy metals written by Dr. John H. Duffus, a toxicologist who is also a member of the IUPAC. I really like the statement that he makes at the end of the introduction.

Quote
Without care for the scientific fundamentals, confused thought is likely to prevent advances in scientific knowledge and to lead to bad legislation and to generally bad decision-making.
-<a href="http://iupac.org/publications/ci/2001/november/heavymetals.html">Heavy Metals - A Meaningless Term</a>

If a big safety watchdog like OSHA decided to strictly follow one of the <a href="http://iupac.org/publications/ci/2001/november/heavymetals_t1.html">definitions</a> of "heavy metals" involving toxicity, then they would probably prohibit the use of all heavy metals outside of laboratories. Most of the world's refineries rely on heavy metals to be used in making alloys, so if these were prohibited, then a large number of products, namely steel alloys, could not be produced. I agree with the statement that Dr. Duffus makes in his conclusion, that heavy metals should be defined based on their bioavailability, with as few exceptions as possible.



Offline abigail07

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Re: heavy metal?
« Reply #3 on: January 19, 2010, 12:24:13 AM »
Actually, I learned that lesson during my high school life. A heavy metal is a member of an ill-defined subset of elements that exhibit metallic properties, which would mainly include the transition metals, some metalloids, lanthanoids, and actinides. Many different definitions have been proposed, some based on density, some on atomic number or atomic weight, and some on chemical properties or toxicity.

Offline Polleke

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Re: heavy metal?
« Reply #4 on: February 20, 2010, 12:36:49 PM »
Actually, I learned that lesson during my high school life. A heavy metal is a member of an ill-defined subset of elements that exhibit metallic properties, which would mainly include the transition metals, some metalloids, lanthanoids, and actinides. Many different definitions have been proposed, some based on density, some on atomic number or atomic weight, and some on chemical properties or toxicity.

Looks a bit like the wikipedia definition ;D

Anyway, its indeed hard to state what a heavy metal is when there is no real meaning or definition for this term.

And it doenst make it easier for me because I am working with copper and iron.. and I wrote those are heavy meatels, but hell, its not even sure or correct.

Offline stewie griffin

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Re: heavy metal?
« Reply #5 on: March 26, 2010, 05:07:12 PM »
Metallica, Megadeth, Pantera, Slayer, etc...  ;)

Offline typhoon2028

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Re: heavy metal?
« Reply #6 on: March 26, 2010, 05:41:10 PM »
metals heavier than iron

Offline 408

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Re: heavy metal?
« Reply #7 on: August 13, 2011, 10:12:07 AM »
Metallica, Megadeth, Pantera, Slayer, etc...  ;)

If those are heavy metal, what are the actinides?   ;)

Offline Fluoroantimonicacid

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Re: heavy metal?
« Reply #8 on: August 20, 2011, 01:45:43 AM »
Metallica, Megadeth, Pantera, Slayer, etc...  ;)

If those are heavy metal, what are the actinides?   ;)
They are a metal group. :D

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