Test Lead at Home: How to Identify Unknown Metals

[pzona]

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]

Let me rephrase. Since it's not radioactive, it is most likely one of the first 82 elements.

Unless it is technetium

 

[pzona]

Geez Borek, you and your exceptions :p

 

[Borek]

They are not mine, they are around

--

 

[DaveC426913]

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]

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.

 

[DaveC426913]

Linotype lead is a precious (and shrinking) commodity.

That is interesting. My brother also speculated that it might be precious, but for a different reason. He said something about low radioactive decay rate of a particular isotope that makes it useful for ... uh ... something to do with shielding.