Bonds Definition and 192 Threads

Hi I've read sufficient literature on Ice/Water expansion to understand that when water freezes into a lattice, the hydrogen bonds between molecules are longer than they are in liquid water, hence ice expands. However, everything I've read seems to skip over the reason why with statements like...

Arrange these bonds in order of increasing bond length. C-I, C-Br, C-Cl, C-F Is there a way to figure this out without drawing molecular orbital diagrams and determining the bond order?

In a 2003 post about electrons and their behavior, which as a rule goes, tended not to get to a final solution, there was a quote by a poster: "There is no chemical bond between chlorine and sodium. That is to say it is only electrostatic attraction, an ionic bond as opposed to a covalent bond...

Hi I am struggling immensely with understand some aspects of chemical thermodynamics: 1) Let's say I have a solid with N atoms and am examining the ionization of individual atoms, and I am supposed to think of the electrons as ideal gasses. Or, 2) a solid or liquid is in thermal equilibrium...

I am curious, for linear conjugated molecules, for example, those with double bonds as in 1, 3-butadiene or 1, 3, 5-hexatriene, how are their double bonds (suppose # of double bonds = N) related to energy levels (n)? From what I gather, those with two double bonds have energy level n =2 and...

Homework Statement I am currently teaching grade 11 chemistry, which isn't really my area. I am trying to find out, in general, whether ionic or covalent bonds are stronger. I am finding a lot of conflicting information online. Homework Equations The Attempt at a Solution Ionic substances...

I took chemistry a couple years ago but never got a satisfactory answer as to why covalent bonds hold molecules together. I understand that they share their outermost electrons, but why would that keep them together? Do the electrons pull against each other or something?

Just double-checking myself on something: Typically at the high-school level, we say that it takes energy to break a bond, but energy is released to form a bond. This has always bothered me because even with a naive understanding of enthalpies we can see formations with different signs. To me...

I think the title says it all. Lemme know if it is unclear.

I'm currently doing my Bachelor's in Physics(1st year). My textbooks aren't too clear on quantum mechanical concepts. "Bonds are formed by overlapping orbitals". I have several questions. I've seen the graph of potential energy versus distance. For some pairs of atoms like hydrogen it dips at a...

Hi, My textbook does not really go into the details of rotation about a bond. I know single bonds can rotate easily. What about double bonds and triple bonds? The pi bonds would be broken. Does that mean new compounds are formed? My textbook says rotation around triple bonds is easy...

Hi, Iam trying to understand the differences between metals, semiconductors and insulators. Regarding the conductivity properties. Iam new to this area so please correct me if I am wrong. I may be simplifying things now; 1) If I put a voltage over a solid, I only measure a current if...

Homework Statement Which of the following compounds contains both 2c-2e bond and 3c-4e bond? A) Be2Cl4 B) B2Cl4 C) (SnCl2)∞ D) both A and C The Attempt at a Solution For 3c-4e bond, there must be 3 atoms present. So correct option should be C but the answer is D.

Hi all, couple of questions in the Official IUPAC naming rules for organic compounds: 1. How do I name organic molecules with both double/triple bonds and substituent? Do I name Both? For ex.: 2-Methyl-4-pentene vs. 2-Methylpentene? 2. If the double/triple bond and the substituent is in the...

We all have been studying chemical bonds, specifically covalent, told to us that it composes of electron sharing between participating atoms. But do we have a scientific evidence that somehow conforms or substantiates this theory? For example, We have evidence to 'believe' in electrons. The...

I read some books which mention about covalent and partially covalent chemical bonds. However, I cannot distinguish between them. Who can help me? Thank you very much!

According to the Molecular orbital theory, diatomic oxygen should have σ2px (internuclear axis) and \pi2py and \pi2pz orbitals filled with two unpaired electrons, one at antibonding \pi2py and the other at antibonding \pi2pz. And of course, the 2s bonding and antibonding orbitals as well...

i think i don't understand the nature of "Binding Energy" very well, and i have a very significant question what iam really intersted in; is the nuclear binding energy, but i think (hopefuly iam right) that it has the same physical nature (NOT origin) as atomic and molecular binding energies...

Silicon has 14 electrons, this means if it fills up its first two shells it will have 4 electrons in the outermost shell (These are the valence electrons). This shell can have 18 electrons in it, so silicon can have 14 more electrons in its outermost shell. This means it could...

I have a question if you have an Hamiltonian given by H = \sum_{i,i+1} \sigma_i \cdot \sigma_{i+1} where i can even or odd bonds so in a 1D lattice so if you have 4 sites(1 2 3 4 1) then (12) and (34) are even bonds and (23) and (41) are odd bonds. and I was checking if [H_{x...

So I was sitting in my very low level biology class today, and we covered some basic chemical concepts that we will need for the class, basics of atoms, the periodic table, sub atomic particles ect... Then we got to the section on bonds, covalent bonds specifically. She showed the typical...

An intramolecular force is a force that holds atoms that form compounds or moleculues together. So if we have NaCl there are a large number of Na+ and Cl- so those ionic bonds hold the ions together so they are considered intramolecular. But say we have a mixture of molten NaCl and CaCl2 and...

Hello, I was wondering how I could go about finding the wavelength of light that would cleave the O-H bonds of a water molecule. I looked up the bond dissociation energy of the O-H bond, and it is 460 kJ/mole. Now, since there are two O-H bonds, it should be twice as much, 920 kJ/mole...

Do intramolecular bonds vibrate in solids...? In case of molecular solids does the Intramolecular bonds(bonds within atoms of a molecule) vibrate as they do vibrate in gas and liquid phases. We are familiar that motion of molecules in solids is in form of vibrations. But when we talk of that...

Do intramolecular bonds vibrate in solids...? In case of molecular solids does the Intramolecular bonds(bonds within atoms of a molecule) vibrate as they do vibrate in gas and liquid phases. We are familiar that motion of molecules in solids is in form of vibrations. But when we talk of that...

How do water molecules behave in the presence of a static electric field? If I apply an electric field on water molecules, would they apply pressure to a solid surface (let's say a noble metal), and if so, what would happen? Could the oxygen wedge in between the atomic gaps on the surface of...

Homework Statement In which of the following pairs of bonds is the shorter bond length not followed by the longer bond length? (1) S―O, P―O (2) C≡C, C=C (3) C=O, C=S (4) C―Si, C―S (5) N≡O, N=O Homework Equations Bond length is determined by the bond order (number of bonds)...

I read in several websites that triple bonds cannot rotate freely. However, I've also read in the book "Chemical Principles" the following lines: "Various types of evidence suggest that the electron density around the two C-O bonds in CO2 is actually cylindrically symmetric—that is, the...

According to chemistry books the ionic and covalent bonds are a different thing. In covalent bonds the electrons share the same space around the bound nuclei, while in ionic bonds two ions are bound by the electric force between the ions. However, the truth is that the wave functions of the...

Can carbon form four bonds with another carbon?

Bonds in molecules What is the meaning of the bonds σ and π in molecules quantum mechanically?

This is not a homework question.

If I had a some covalent molecules with a total intermolecular bond strength of 100J and total covalent bond strength of 100J and when I supply 100J of heat into those molecules, how are the bonds going to break? Will both bonds break simultaneously or will one bond break in preference to the...

Hello, I am looking at the sigma and pi bonds and trying to understand them. I know that the bond is the overlap of the orbitals, in the case of sigma bonds two s-orbitals and the pi bonds is the p-orbitals. When you have the sp hybrid orbitals, how are there only the same number of hybrid...

Hi! I study semiconductors and I am confused with the bonding picture for semiconductor crystals. For example, it is said that in Si crystal one can find covalent bonds. In the most books this bonds are shown like that: 2D crystal structure where lines between atoms are a covalent bonds, each...

Hello, I have never been able to keep straight in my head if making bonds and breaking bonds are exothermic or endothermic. Is there any way that someone can explain why which is which in a way that is understandable because I'm tired of constantly having to re memorize it.

Homework Statement We know that the average kinetic energy of an ideal gas atom or molecule at Kelvin temperature T is (3/2)kbT. For what temperature T_He does the average kinetic energy of an ideal gas atom or molecule equal the bond energy of the van der Waals bond in He_2 7.9*10^-4 ev...

Homework Statement Which has the strongest ionic bond? Cs2Se AlN CaI2 Kbr Homework Equations Look at electronegativities The Attempt at a Solution I looked at electronegativities and found the differences. The largest difference was KBr. But apparently, that was wrong. See EN differences...

Does heat weaken the strength of chemical bonds?

Homework Statement find total sigma and pi bonds in c6h6 Homework Equations Benzene structure The Attempt at a Solution if i consider benzene structure, then total will be 12σ and 3∏ but according to the random structure that i managed to draw, it showed, 11σ and 4∏, was i wrong...

Homework Statement In the hybradization of ethyne molecule, how many σ and ∏ bonds are being formed? The Attempt at a Solution Since, there is a triple bond between the carbon atoms, it should form 2 ∏ bonds and 1 σ bond. Relatively there will be 2 other σ bonds between Carbon-Hydrogen...

hello! do you know articles or textbooks with as much as possible info about peptide bond? when you want to gather info about a bond, which parameters are you looking for? thanks!

I stumbled across diborane yesterday and was quite surprised to see the "bent bond" structure it utilizes as well as the hydrogens serving as a connection between the boron atoms. Are there any other unique bonds like this? All I had been taught about was covalent, resonance type/aromatic...

Homework Statement Homework Equations Peptide bonds DO NOT BREAK DOWN when proteins/enzymes are denatured. Peptide bonds form the primary structure of proteins and enzymes. All of the textbooks here are my sources...

I've learned about the Band Theory of metallic bonds and how they produce color, but how does a covalent bond produce color? Normally a metal such as iron absorbs and emits back the full range of colors due to metallic bonds, but when oxygen or sulfur get added it produces a different color. Can...

Can anyone list these bond types in ascending order based on their strengths ionic bonds, covalent bonds, metallic bonds, hydrogen bonds, van der waals forces

Curious about the wave functions of elections shared in covalent bonds. If you have two hydrogen atoms w elections in the lowest energy state with the same spin and they join together to form a molecule H2 The spin of one of the elections will change (randomly?) The electons of the two...

Here is a screenshot of a slide that the professor went over in class (PV = Present Value): http://dl.dropbox.com/u/64325990/ECON%20102/Capture.PNG I think the reason why I don't understand what's going on in the math is because I don't understand the question at all. So the bond pays $100...

I am having difficulties understanding the concept of hybridization and the σ and ∏ bonds. My current understanding is that basically you just mix up a p and s orbital and it gives you an sp orbital, and if the bonds touch they are σ bonds, and if the bonds are parallel the are ∏ bonds. I don't...

Hello everybody. I would like to ask the following: Imagine a source of strong electric filed. For example a positively charged metal sphere. Then we put a small (relatively to the source of the electric field) metal object in the electric field. Electron inside the metal move in such way, that...