Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

LPF Donation via Stripe | LPF Donation - Other Methods

Links below open in new window

ArcticMyst Security by Avery

Sodium metal

Joined
Jun 22, 2011
Messages
2,431
Points
83
Hi guys, here I am again with another chemistry thread!

Managed to buy a small chunk of elemental Na, which is something I've wanted for a very long time for my collection (of random stuff) but never managed to get my hands on.

It came in a sealed bag, which I still haven't touched because I need to buy some mineral oil to store it. Local drugstores sell Nujol and a quick search indicates that it is indeed used for Na storage. Which brings me to my question: is there a "best" type of mineral oil for this kind of storage?

I don't intend to do any reactions with it (besides throwing a small piece on water, of course ;P) but I'd like to keep the purity if possible.
 
Last edited:





Joined
Jul 4, 2008
Messages
2,499
Points
113
Hi guys, here I am again with another chemistry thread!

Managed to buy a small chunk of elemental Na, which is something I've wanted for a very long time for my collection (of random stuff) but never managed to get my hands on.

It came in a sealed bag, which I still haven't touched because I need to buy some mineral oil to store it. Local drugstores sell Nujol and a quick search indicates that it is indeed used for Na storage. Which brings me to my question: is there a "best" type of mineral oil for this kind of storage?

I don't intend to do any reactions with it (besides throwing a small piece on water, of course ;P) but I'd like to keep the purity if possible.

Simple USP "pharmacy grade" mineral oil (baby oil) will work to keep the air away from your sample. Nujol is a brand of mineral oil...so yes both are the "best" kinds of oil for storing your sample. :)
 
Joined
Dec 11, 2011
Messages
4,364
Points
83
Excellent! I love the alkali metals! I used to have a 10g chunk of K (potassium) about 15 years ago. I wish I would have kept it; when I went away for summer one year my parents tossed it out (woe to the garbage men that day!). I also lost 10g of Gallium that day :(.

Yep, regular old mineral oil is best, just make sure it is pure and not tainted with chemicals meant for topical application benefits. Be careful about the generation of superoxides on the surface as they are explosive.
 
Joined
Jun 22, 2011
Messages
2,431
Points
83
Sounds good guys, I'll try and get some tomorrow :)

I have a sample of Gallium here, gotta love how it melts on your hand!
Have you seen the experiment where you put some of it on an Al can and it makes a "crappy" alloy that you can easily tear the can? I'd try that but then again this kind of stuff is really hard to come by around here...

Perhaps one day I'll do one of those periodic tables with real samples for all the stable/non-radioctive elements. That'd be neat!
 
Joined
Dec 11, 2011
Messages
4,364
Points
83
Yup, that's the reason gallium cannot be shipped by air in the US. If even a drop of it makes it to the aircraft structure it will permeate into the metal causing destruction along its entire path. I've seen where a 2g sample completely destroyed a 2KG Al I beam in under a week.
 
Joined
Jul 4, 2008
Messages
2,499
Points
113
Sounds good guys, I'll try and get some tomorrow :)

I have a sample of Gallium here, gotta love how it melts on your hand!
Have you seen the experiment where you put some of it on an Al can and it makes a "crappy" alloy that you can easily tear the can? I'd try that but then again this kind of stuff is really hard to come by around here...

Perhaps one day I'll do one of those periodic tables with real samples for all the stable/non-radioctive elements. That'd be neat!

If you ever need radioactive element samples drop me an email.
small samples are not as hazardous as one might think, especially sealed and behind glass.
You'll be surprised at just how many Radioactive elements can be found around your house!! :e.g.:

Sigurthr's comment on Sodium superoxide is quite accurate...
NaO2 is prone to sudden decomposition upon exposure to moist air and has lead to several well documented explosions.
Look for a yellow crust on the Sodium metal. This is generally a good indication of the age of the sample as well. Older samples are quite often crusted with NaO2.
 
Last edited:
Joined
Dec 11, 2011
Messages
4,364
Points
83
Hmm, I would LOVE a sample of metallic Thorium, I nearly won one on eBay years ago before they started making it impossible to list such things.

Depleted uranium samples are relatively easy to come by in sub-gram quantities too. Finding larger chunks is quite difficult and expensive. They make excellent planar field sources and radiation shielding though. I remember Geo K0FF had a slab that IIRC was 6" x 10" x 1/4" and was worth a new small car.
 
Joined
Jul 4, 2008
Messages
2,499
Points
113
Hmm, I would LOVE a sample of metallic Thorium, I nearly won one on eBay years ago before they started making it impossible to list such things.

Depleted uranium samples are relatively easy to come by in sub-gram quantities too. Finding larger chunks is quite difficult and expensive. They make excellent planar field sources and radiation shielding though. I remember Geo K0FF had a slab that IIRC was 6" x 10" x 1/4" and was worth a new small car.

:san:I'll look around for some Thorium metal for you if you want... :wave::wave:

... I'll see what can be sourced!

:can:
 
Joined
Jan 14, 2009
Messages
1,452
Points
83
I used clear mineral oil I got from ebay for my sodium sample , still perfect after 2.5 years :D
 
Last edited:
Joined
Jul 4, 2008
Messages
2,499
Points
113
I used clear mineral oil I got from ebay for my sodium sample , still perfect after 2.5 years :D

NaO2 will form eventually even under oil... it takes quite some time to do this however.
Lots of older samples from the 70's and early 80's have this yellowish outer coating to them.

I love chemistry and I especially love element collecting!!!

So far, my favourite alkali metal is Potassium as it contains a very detectable amount of naturally occcuring radioactive isotope Potassium 40.

:) :tinfoil::tinfoil::tinfoil::tinfoil:

My favourite elements that I have isolated myself are Arsenic (easy), Tellurium from Tellurite and Uranium from homemade Uranyl Nitrate which was made from some massive gummite with Autunite from Spokane Wa. VERY hot stuff!! Lots of fun doing the extraction though!!! :D
 
Joined
Jan 14, 2009
Messages
1,452
Points
83
NaO2 will form eventually even under oil... it takes quite some time to do this however.
Lots of older samples from the 70's and early 80's have this yellowish outer coating


That's true , good thing sodiums shelf life is a lot longer than potassium due to its ease of forming superoxides .

Hopefully my sodium lasts .....

Sodium is my faviourte , especially when it's in low pressure sodium lamps .
 
Last edited:
Joined
Jul 4, 2008
Messages
2,499
Points
113
That's true , good thing sodiums shelf life is a lot longer than potassium due to its ease of forming superoxides .

Hopefully my sodium lasts .....

Sodium is my faviourte , especially when it's in low pressure sodium lamps .

Yes, I bet you're going to have to have great self control not to be tempted to chuck that lump of sodium into a bucket of warm water!! Right?

:eg: :eg:

I guess I don't have to tell you about our Alkali metal snowballs we used to make in middle school many many years ago. Those were great fun! :D
 
Joined
Dec 11, 2011
Messages
4,364
Points
83
The great thing about K40 is that we all have it!

I do miss my K lump. So much fun!

I once saw a 2lb log of K in a video... /drool!.

United nuclear used to sell individually foil wrapped Na chunks for like $25. I don't know if they still do. This was back when u could get 3g of DU for $45.
 
Joined
Jun 22, 2011
Messages
2,431
Points
83
I'll pass on the radioctive elements, at least for a long time, I still have a lot of stuff to get before that :p

I'll keep an eye for the superoxide coat. Do you guys figure I should submerge the sealed bag on the oil before opening and releasing the sample?

BTW what are alkali snowballs?

The united nuclear store has a LOT of cool stuff. I'd be all over it if I could!

I do have a few cool substances here: a nice block of pyrolytic carbon, some silica aerogel, a small bottle of ferrofluid (wonderful but incredibly messy)
 
Joined
Jul 4, 2008
Messages
2,499
Points
113
I'll pass on the radioctive elements, at least for a long time, I still have a lot of stuff to get before that :p

I'll keep an eye for the superoxide coat. Do you guys figure I should submerge the sealed bag on the oil before opening and releasing the sample?

BTW what are alkali snowballs?

The united nuclear store has a LOT of cool stuff. I'd be all over it if I could!

I do have a few cool substances here: a nice block of pyrolytic carbon, some silica aerogel, a small bottle of ferrofluid (wonderful but incredibly messy)

Nope... that's ok. Just place the sodium into the oil. The superoxide doesn't form quickly even in open air. Don't leave the sample out for any extended length of time in air. This will cause the superoxides to form. Sodium will take it's time, more reactive elements like K, Rb and Cs can form superoxides within a minutes or so.

Alkali snowballs are a snowball with a small chunk of Calcium metal
dropped into the centre and then thrown by hand.

~~ :tinfoil: Ah, the Radioactive elements are pretty interesting and are strangely addictive. One can never have enough Uranium as I have discovered. It's salts are amazing greens, yellows and reds. Uranyl Nitrate is fluorescent under long wave UV. Most importantly it makes my Geiger counter sing like a hyperactive locust!
 
Last edited:
Joined
Dec 11, 2011
Messages
4,364
Points
83
I was tempted to get a bag - yes you read right - a 1lb BAG of uranyl nitrate once as it was quite inexpensive but the contamination worries were just too much for me.
 




Top