which substance melts at the highest temperature? (1 Viewer)

[andrew markworthy]

My ten year-old son has just asked me this question and I'm stumped. I know that of the elements, carbon melts at the highest temperature (though tungsten has the highest boiling point). However, are there any compounds with a higher melting point, please?

 

[Chris]

hafnium carbide I believe has the highest compound melting point.

 

[CharlesD]

Carbon has a very high melting point.. something like 3500 C
it might have the highest melting point of any element, but its been a long time since I last had a Chemistry class

 

[Chu Gai]

Of pure elements, it's carbon. Of metallic elements it's tungsten.

 

[Rob Gardiner]

Of dessicants, I'd be surprised if it wasn't silica.

 

[Trey Fletcher]

Jay H, you've just been paged!!!

 

[Jay H]

I have? Speaking of silica, bought some more hiking boots on saturday (Montrail Torres GTXs) and in it had a tiny little pillow of silica. I feel warm and fuzzy now...

Jay

 

[andrew markworthy]

Thanks for the answers, guys. Well, some of them, anyway.

 

[David-S]

Tantalum or Hafnium carbide, both around 3900*C, and diamond, right around 4000*C (Note, ~7000*F)

• 1 Hafnium Carbide, HfC 3900
• 2 Niobium Carbide 3500
• 3 Tantalum Carbide 3880 - 3915
• 4 Titanium Carbide, TiC 3065
• 5 Zirconium Carbide 3400
• 6 Graphite, Carbon, C 3650
• 7 Boron Nitride, 100% BN, (Borazone) 3027
• 8 Advanced Ceramics Corp. Tantalum Carbide (TaC) Coating 3880
• 9 Advanced Ceramics Corp. Niobium Carbide (NbC) Coating 3760
• 10 Advanced Ceramics Corp. Zirconium Carbide (ZrC) Coating 3540
• 11 Advanced Ceramics Corp. Pyrolytic Graphite (PG) Coating 3650
• 12 Advanced Ceramics Corp. "PG" Pyrolytic Graphite 3650
• 13 Diamond, Natural 4027
• 14 Hafnium Nitride, HfN 3305
• 15 Niobium Carbide, Nb2C 3080
• 16 Niobium Carbide, NbC 3608
• 17 Tantalum (IV) Sulfide, TaS2 3000
• 18 Tantalum Boride, TaB2 3140
• 19 Tantalum Carbide, Ta2C 3327
• 20 Tantalum Nitride, TaN 3090
• 21 Thorium Oxide, ThO2 (Thorianite) 3390
• 22 Titanium Boride, TiB2 3225
• 23 Titanium Nitride, TiN 3290
• 24 Zirconium Boride, ZrB2 3245
• 25 Zirconium Carbide, ZrC 3532asdf

(from www.matweb.com )

 

[andrew markworthy]

David, that is brilliant - many thanks.

 

[Wayne Bundrick]

Who would have thought that "Fool's Diamond" (Zirconium) would be so high on the list?

 

[Kevin Farley]

That always made me confused; if all matter melts, would trees melt at a certain temp?

 

[Joseph DeMartino]

All matter doesn't melt. Depending on the nature of the chemical bonds, some materials simply burns without ever becoming liquid. Metals and minerals (as above) have crystaline structures and they will melt at a high enough temperature. Most of the stuff that makes up plants and animals doesn't have a crystaline structure. So no, a tree won't melt, it will burst into flames before it could reach any theoretical "melting point" for cellulose or other major components of wood.

Regards,

Joe

 

[Andrew Testa]

No, trees wouldn't melt since they aren't a solid. It's not that all matter melts, but that all solids melt, with the understanding that you aren't at the pressures where it sublimates directly to gas. Trees are made of many different solid compounds, but are mostly liquid. And those many compounds have significant reactions at temperatures well below their melting points. You'll boil off all the liquids, and the organic solids will react with each other in a process scientists call "fire" to release the energy stored in the structures. The remaining solid compounds, mostly carbon, will then melt once the proper temperature is reached. So while some parts of a tree will eventually melt, a tree will never melt from its original form.

Andy

edit: Bah, Joe beat me to it.

 

[Jay H]

Then somebody explain the wicked witch in the Wizard of Oz?

"I'm melting...."

Jay

 

[Wayne Bundrick]

She didn't melt, she dissolved. She was water soluble, much like the ability of many people to drive their vehicles.

 

[Joseph DeMartino]

Oh, is that what it is. My working theory up until now is that rainwater reduces IQ in certain individuals.

Regards,

Joe

"I want to die the way my grandfather did, in his sleep. Not screaming and begging like those poor bastards in his car"

 

[Chris]

Hot damn! I knew I subscribed to Science magazine for a reason, I actually got that one right!