- #1
photon79
- 60
- 0
which is the strongest of all the chemical bonds? metallic or covalent?
Which Bond is Stronger: Metallic or Covalent?
- Context: High School
- Thread starter photon79
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Discussion Overview
The discussion centers on the comparative strength of metallic and covalent bonds, exploring various perspectives on bond strength, melting and boiling points, and the structural implications of different types of bonding. Participants examine theoretical and practical aspects of bond strength in the context of different materials.
Discussion Character
- Debate/contested
- Technical explanation
- Conceptual clarification
Main Points Raised
- Some participants question whether metallic or covalent bonds are stronger, with one noting that diamond, formed by covalent bonds, is exceptionally strong.
- Another participant suggests that bond strength can be inferred from melting temperatures, mentioning tungsten as having the highest melting temperature among elements.
- There is a discussion about the properties of carbon in different structures, such as graphite and diamond, and how these affect perceived hardness and bond strength.
- Participants provide estimates of bond energy strengths, indicating that ionic bonds may be stronger than covalent and metallic bonds, but there is variability in the values presented.
- One participant argues that melting temperature is not a reliable indicator of bond energy, suggesting that boiling points may be a better measure, citing rhenium and tungsten as examples of materials with high boiling points.
- There is mention of the complexity in calculating bond energies, particularly in transition metals, and a desire for resources to learn more about these calculations.
Areas of Agreement / Disagreement
Participants express differing views on the strength of metallic versus covalent bonds, with no consensus reached. Some argue for the strength of covalent bonds in certain materials, while others emphasize the significance of metallic bonds and boiling points.
Contextual Notes
Limitations include the variability in reported boiling points and bond energy values, as well as the complexity of bond interactions in transition metals, which may not be fully resolved in the discussion.
- #2
Bladibla
- 357
- 1
Metallic, or ionic.
- #3
photon79
- 60
- 0
but the strong diamond is foemed by covalent bond!
- #4
Facial
- 30
- 1
I really don't know, and that's a pretty darn good question. I'd like to know myself from some of the experts.
You can probably tell the bond strength roughly by the melting temperature of the solid, which is where interatomic interactions partially break loose. In this case, tungsten is the solid with the highest melting temperature (at STP) of any element.
But if you take a look at carbon, which essentially is a covalent network solid, it sublimes at a temperature just above tungsten's melting point. This suggests that covalent bonds can be quite tough as well.
The highest melting of any ionic solid that I have encountered is MgO, which liquefies at just over 2800 C. Pretty impressive.
You can probably tell the bond strength roughly by the melting temperature of the solid, which is where interatomic interactions partially break loose. In this case, tungsten is the solid with the highest melting temperature (at STP) of any element.
But if you take a look at carbon, which essentially is a covalent network solid, it sublimes at a temperature just above tungsten's melting point. This suggests that covalent bonds can be quite tough as well.
The highest melting of any ionic solid that I have encountered is MgO, which liquefies at just over 2800 C. Pretty impressive.
- #5
- 32,812
- 4,723
The crystal structure can determine the bond length, and thus, the "hardness". For example, if you look at graphite, the c-axis bonds are very long when compared to the in-plane bonds. So graphite appears to be "soft" simply because one can "shave off" sheets of graphite structure.
On the other hand, the same carbon atoms when arranged in a hexagonal closed-pack, will have extremely short bond length. This produces a stronger material, even when the atom and the type of bonding are the same as graphite.
Zz.
On the other hand, the same carbon atoms when arranged in a hexagonal closed-pack, will have extremely short bond length. This produces a stronger material, even when the atom and the type of bonding are the same as graphite.
Zz.
- #6
fasterthanjoao
- 730
- 1
They overlap.
Bond energy strengths can be taken roughly as:
Ionic 5ev (per bond) {with a boiling dissociation >1000K}
covalent 1-5ev (per bond) {boiling dissociation >1000K for non-molecular solids}
metallic 1-2ev (per atom) {boiling dissociation 1000K}
----
intermolecular: hydrogen 0.5ev (per bond)
van der waals 0.1 per atom (or formula unit)
Bond energy strengths can be taken roughly as:
Ionic 5ev (per bond) {with a boiling dissociation >1000K}
covalent 1-5ev (per bond) {boiling dissociation >1000K for non-molecular solids}
metallic 1-2ev (per atom) {boiling dissociation 1000K}
----
intermolecular: hydrogen 0.5ev (per bond)
van der waals 0.1 per atom (or formula unit)
- #7
fargoth
- 318
- 6
melting temperature isn't a good indicator for bond energy - the boiling point is a better measure.
it seems from what i found so far that Rhenium (with 5627.0 °C boiling temperature) is the matter with the highest bonding energy.
after that you get Tungsten (with 5555°C boiling temperature).
(note that at high temperatures like these the values arent accurate, litterature gives more then one value here for the boiling points, but I am pretty sure that Rhenium has higher boiling temperature...)
while Carbon boils at 4827°C
anyway, i don't know how to calculate these values...
it'll be interesting if anyone around here knew it.
it seems from what i found so far that Rhenium (with 5627.0 °C boiling temperature) is the matter with the highest bonding energy.
after that you get Tungsten (with 5555°C boiling temperature).
(note that at high temperatures like these the values arent accurate, litterature gives more then one value here for the boiling points, but I am pretty sure that Rhenium has higher boiling temperature...)
while Carbon boils at 4827°C
anyway, i don't know how to calculate these values...
it'll be interesting if anyone around here knew it.
- #8
fargoth
- 318
- 6
fasterthanjoao said:
but the two matterials with highest boiling points are metals!
i haven't found any ion matterial that has higher boiling point...
can you point me where i could learn to calculate the exact bond energy?
- #9
fargoth
- 318
- 6
oops, haven't seen ZapperZ answered the OP...
id still like someone to show me where i could learn more about calculating bond energies though...
id still like someone to show me where i could learn more about calculating bond energies though...
- #10
Pieter Kuiper
- 142
- 0
Covalent bonding is also important in transition metals. It is difficult to distinguish between these contribution. It is all calculated by the same programs.
When considering bonds, one might take into consideration that carbon i diamond only has only four bonds to nearest neighbours, where tungsten has eight (at room temperature) and rhenium has twelve.
When considering bonds, one might take into consideration that carbon i diamond only has only four bonds to nearest neighbours, where tungsten has eight (at room temperature) and rhenium has twelve.
- #11
Intuitive
- 270
- 0
hexagonal density makes for some very tough Material.
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