The bond between HI is a polar covalent bond. It is because Hydrogen is electropositive in nature in comparison to Iodine. So, the bonding is covalent but it has partial polarity in charges.

HI is a polar molecule because of the electronegativity difference of Iodine (2.66) and hydrogen (2.2) atom which causes the formation of partial positive and negative charges on both ends of the molecule, as a result, the molecule has a net dipole moment.

The electronegativity values of the two bonding atoms highly affect the polarity of the bond between the atoms. The difference in electronegativities between bonded atoms can indicate whether a bond is polar, non-polar or ionic. Hence, the H-I bond is also polar. Thus, both H-F and H-I bonds are polar covalent bonds.

From the tables, the Electronegativity Value for H is 2.20. From the tables, the Electronegativity Value for Cl is 3.16. 3.16 – 2.2 = 0.96 Since 0.96 is between 0.4 and 1.7, the type of bonding in HCl is Polar Covalent. Covalent bonding is an example of intramolecular bonding.

Notice that one of the oxygen atoms from the original O2 molecule shown in black has contributed both electrons to the blue oxygen atom. The blue oxygen atom has not contributed electrons to this bonding pair of electrons, so this is a coordinate covalent bond (dative bond).

HI < HBr < HCl < HF. – With the increase in size and decrease in ionization enthalpy, the covalent character decreases. – So, HCl has less covalent character than HF and HBr has less covalent character than HCl. – HI has the least covalent character due to the above given reasons.

The overlapping is more as compared to HCl or HBr or HI. Due to this strong bonding and extensive overlapping of orbitals it is difficult for the given compound to release hydronium ions in water. This makes HF a weaker acid despite its high electronegativity.

Now if we compare the bond strength between HI and HCl we find that the HI bond is weaker as Iodine is much larger than chlorine and cannot form an effective overlap between the s orbital of Hydrogen and the p orbital of Iodine, so relatively the H-Cl bond is stronger due to the better overlap of the sigma bonds.

Only dispersion forces are present and these are largest in the longer chain alkane as it has more electrons (more bonds). Both molecules possess dipole moments but CH3CH2OH contains hydrogen bonded to an electronegative element so H-bonding is possible.

Hydrogen bonds are strong intermolecular forces created when a hydrogen atom bonded to an electronegative atom approaches a nearby electronegative atom. Greater electronegativity of the hydrogen bond acceptor will lead to an increase in hydrogen-bond strength.

Why are hydrogen bonds stronger than dipole-dipole forces which are stronger than dispersion forces? Dipole is permanent, so the attraction is stronger. With hydrogen bonds you can only see attraction between molecules that are polar. This attraction increases with the increasing total number of electrons.

Bose-Einstein condensates

gases

The three states of matter are: Solids: The strong bonds between molecules make solids rigid and very difficult to deform. Liquids: The relatively weak bonds between molecules allow liquids to be deformed without effort.

gas

Solids: have a fixed shape and cannot flow, because their particles cannot move from place to place. cannot be compressed (squashed), because their particles are close together and have no space to move into.

Because the particles can move, liquids don’t have a definite shape, and they can flow. Because the particles are still packed close together, liquids can’t easily be compressed and keep the same volume.

A liquid is made up of tiny vibrating particles of matter, such as atoms, held together by intermolecular bonds. Like a gas, a liquid is able to flow and take the shape of a container. Most liquids resist compression, although others can be compressed.