Note: I've already handed this in for homework and got the question wrong but don't understand why. Not looking for someone to do my homework for me, just trying to flesh out an area where I'm not yet proficient.
This is problem 4.10 from the book "Nanotechnology: Understanding Small Systems" 2nd ed. by Rogers, Pennarthur, and Adams.
The exact wording of the problem states:
"Rank the following bonds from strongest to weakest and provide the bond energy: the bond between hydrogen an oxygen in a water molecule; the bond between sodium and chloride in the NaCl molecule; the bond between atoms in a metal; the van der Waals bond between adjacent hydrogen atoms."
I've found the exact bond strength of 3 of 4 of these.
Na+ - Cl- bond = 830 zJ or 8.3E-19 J H-O bond = 760 zJ or 7.6E-19 J H-H bond = 0.14 zJ or 1.4E-22 J
What I cannot find is the bond strength for metal-to-metal atoms. I tried specifically looking for copper, silver, and iron and couldn't find the bond strength between atoms.
To complicate things further, this question has been asked numerous times in various iterations and other answers have stated that covalent bonds are stronger than ionic bonds, which are in turn stronger than metallic bonds. Everyone agrees H-H bonding is weakest.
So is it just the case that Na-Cl is a particularly strong ionic bond and H-O is a particularly weak covalent bond such that this particular ionic bond is stronger than this particular covalent bond? Or are the other answers incorrect?
I should probably also note that based off of copper's heat of vaporization of 3630 J/g and its molar mass of 63.546 g/mol I calculated a bond strength of 383 zJ and WRONGLY concluded:
ionic > covalent > metallic > H-H (van der Waals)
So I got the question marked incorrect which probably means I didn't do the calculation for copper's bond strength correctly.