home test for lead


by DaveC426913
Tags: home, lead, test
mrjeffy321
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#19
Sep22-09, 12:19 AM
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Lead in its solid, elemental, form can be slowly absorbed into your body by touch. Minor contact with it here and there is generally no big deal by itself. But it accumulates in your body over time and might eventually reach dangerous levels from chronic exposure.

Although absorption of solid lead into the body is relatively slow, water-soluble lead salts on the other hand are much more readily absorbed and pose a much greater danger. It is best to only generate and use lead salts in moderation and it dispose of them through the proper channels. Many cities have an environmental-waster disposal facilities where people can bring them their waste (such as lead paint, motor oil, …., other nasty stuff that should not end up in landfills or down the drain) and they will dispose of it for you for free. This would be the preferred way for an individual to dispose of lead waste.

Lead shavings also pose a greater risk compared with just a large solid lump of lead metal since there exists the possibility of breathing in some of the smaller flakes or accidentally ingesting them. So one might be wise to wear a mask and wash one’s hands thoroughly while / after handling fine flakes of lead.
chemisttree
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#20
Sep23-09, 12:45 AM
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He still hasn't determined if his lump of metal fogs unexposed film.....

It could be worse, y'know.
Dadface
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#21
Sep23-09, 02:34 AM
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I think it's kryptonite.
Borek
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#22
Sep23-09, 03:02 AM
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Nah, IIRC kryptonite was green.
DaveC426913
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#23
Sep23-09, 08:25 AM
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Quote Quote by Borek View Post
Nah, IIRC kryptonite was green.
That depends. What colour are the Frogstar Fighters in your universe?
DaveC426913
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#24
Oct1-09, 08:10 AM
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OK, radioactivity: zero.

I would not have been amused to find out that I've been storing a lump of Plutonium on my office shelf....
pzona
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#25
Oct1-09, 10:49 AM
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Well the good news is since it's not radioactive, it has to be one of the first 82 elements, so lead is still a possibility. Also, you don't have to worry about pesky radiation messing with your cells :)
Borek
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#26
Oct1-09, 10:55 AM
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Quote Quote by pzona View Post
Well the good news is since it's not radioactive, it has to be one of the first 82 elements
Unfounded speculation.

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DaveC426913
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#27
Oct1-09, 12:12 PM
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Quote Quote by Borek View Post
Unfounded speculation.
How so? It could be a higher element yet not be radioactive?



Why is your sig part of the body of your message?
chemisttree
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#28
Oct1-09, 12:25 PM
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Perhaps he is referring to Bismuth (atomic # 83).
turbo
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#29
Oct1-09, 12:31 PM
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Quote Quote by DaveC426913 View Post
How so? It could be a higher element yet not be radioactive?
Thorium 232 has a half-life of over 14Gy, so you might not be able to detect much radioactivity. Chances of you having a decent-sized chunk of it hanging around your house are pretty slim, though.
chemisttree
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#30
Oct1-09, 12:35 PM
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Same is true for Bismuth 209. Half life something like 2 X 1019 years.
pzona
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#31
Oct1-09, 12:48 PM
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Let me rephrase. Since it's not radioactive, it is most likely one of the first 82 elements. I understand that some higher elements could fall into this category (for example, bismuth-209, as was said), but how often do these elements present themselves in such large quantities in everyday life?
Borek
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#32
Oct1-09, 02:02 PM
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Quote Quote by pzona View Post
Let me rephrase. Since it's not radioactive, it is most likely one of the first 82 elements.
Unless it is technetium
pzona
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#33
Oct1-09, 11:08 PM
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Geez Borek, you and your exceptions :p
Borek
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#34
Oct2-09, 02:49 AM
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They are not mine, they are around

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DaveC426913
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#35
Oct2-09, 10:33 PM
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OK, I took my sample into my brother's lab to test its density.


We measured its volume by dropping it in a full beaker of water and measuring the weight (and thus volume) of the water that was displaced on a microgram scale. By far the biggest problems we had were:
- eliminating the meniscus so we cold get an accurate water level, and
- ensuring that we drained all drops from the exteroir of the beaker onto the weight scale.

We used combinations of alcohol and/or hand soap to minimize the meniscus and used a microlitre pipette to recover any drops that lingered on the beaker. My brother, having spent decades in the lab, was able to estimate the few microlitre drops remaining and added them to the test sample. We figure we got our volume measurements to within +/-20 microlitres. We did the experiment 3 times.

Results:
The sample weighs 116.06g.
The volume is 10.13, 10.56 and 10.64 cm^3 for an average of 10.44 cm^3.

This results in a density of 11.12g/cm^3 +/- 0.02.

The published density of common lead is 11.34g/cm^3.

My measurement of the sample is within 2% of the density of lead.

I'm callin' it lead.
turbo
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#36
Oct3-09, 04:11 AM
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Quote Quote by DaveC426913 View Post
OK, I took my sample into my brother's lab to test its density.


We measured its volume by dropping it in a full beaker of water and measuring the weight (and thus volume) of the water that was displaced on a microgram scale. By far the biggest problems we had were:
- eliminating the meniscus so we cold get an accurate water level, and
- ensuring that we drained all drops from the exteroir of the beaker onto the weight scale.

We used combinations of alcohol and/or hand soap to minimize the meniscus and used a microlitre pipette to recover any drops that lingered on the beaker. My brother, having spent decades in the lab, was able to estimate the few microlitre drops remaining and added them to the test sample. We figure we got our volume measurements to within +/-20 microlitres. We did the experiment 3 times.

Results:
The sample weighs 116.06g.
The volume is 10.13, 10.56 and 10.64 cm^3 for an average of 10.44 cm^3.

This results in a density of 11.12g/cm^3 +/- 0.02.

The published density of common lead is 11.34g/cm^3.

My measurement of the sample is within 2% of the density of lead.

I'm callin' it lead.
You could have a slug of "printer's lead". It was used for linotype printing and is cut with antimony (and perhaps a little tin) so that it is hard enough to resist deformation when making multiple impressions on a printing press, yet still re-melt easily for re-use.

Edit: hand-loaders love this stuff, since it can be easily cast into bullets, and it is "just" hard enough to shoot a (warning! Scientific term coming!) gazillion times without causing lead deposition in the grooves of a rifled barrel. Commercially, this tendency is overcome by jacketing bullets in copper or some other metal or alloy, but hand-loaders don't have the capability of producing jacketed bullets. Linotype lead is a precious (and shrinking) commodity.


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