Whichone of the intermolecular forces exist between the inert gas atoms in the liquid state like He(l)?
151202
All molecules are experience London Dispersion, or induced dipole-induced dipole forces.\n\nConsider He.  When both electons in the electron cloud are spontaneously bear one another, this causes a partial negative charge on one side of the atom and a partial positive charge on the other side.  This 'dipole' can then induce a dipole moment on another He atom.  London dispersion forces are relatively weak and exponentially dependent on the distance between atoms- so they must be relatively close to one another.
754160
The force between two atoms depends on the distance between them. If they are far away from each other they don't feel each other so the force between them is 0 and typically one defines the potential energy to be 0 when the atoms are infinitely far away from each other. If you move the atoms closer together there will be an attractive electromagnetic force between them (the so-called van der Waals force) meaning that the potential energy decreases. At even shorter distances the force becomes stronger, because the electrons in one atom begin to feel the attractive potential of  the positively charged nucleus of the other atom. At some point the energy reaches a minimum. If you try to move the atoms closer together they will repel each other and the potential energy increases towards plus infinity meaning that it is impossible to put the atoms on top of each other (because of Paulis exclusion principle if you have heard of that. Roughly speaking it states that electrons are not allowed to overlap each other in space). So to summarize the interatomic potential goes from 0 at large distances through a negative minimum towards infinity at small distances (the simplest and most commonly used model potential for interatomic interactions is the Lennart Jones potential which is Ar^-12-Br^-6 where A and B are positive constants which are different for different atoms and r is the distance between the two atoms. Try to play around with such a function if you want to get a feeling for it).\n\nMolecular bound states can be formed where the potential is negative. The ground state (lowest potential energy) will have an energy close to the minimum and the most loosely bound states will have a potential energy close to zero meaning that the atoms in such a molecule will mostly feel the van der Waals part of the potential which governs the region where the atoms are far away from each other - that's the long-range part of the interatomic potential.\n\nHope that helps...
108781
Surface Tension = An attractive force between water molecules called hydrogen bonding.
126982
Solids, whether pure elements or in general, are crystals made up of ions or molecules, or in rare cases like diamond a single compound of covalent bonds. The thermal stability of a crystal depends on the electrostatic (electrical charge, dipol or quadrupol) property of the constituents and their orientation, as well as their ability to retain constituents placed on the surface to the liquid. Electrostatic forces depend on the charge (or partial charge in case of dipols) and the inverse squared distance of the charges. Quadrupol forces aka Van der Waals forces depend on the inverse sixth potency of the charge.\n\nUsually crystals made up of molecules break up into single molecules when melting. In the liquid these molecules still interact with each other, until at boiling point these interactions aren't strong enough to retain the molecules in the liquid. Crystals made up of ions create ionic melts held together by electrostatic attraction. This isn't found for pure elements, though. Metals are similar in the liquid and solid state, with ionized atoms surrounded by a dislocated electron cloud. Covalently bonded crystals don't melt, but may transform into different compounds.\n\nNote that most elements have several different solid states.\n\nElemental carbon can be found as monomer or low-count polymer fragments in the gaseous phase, no liquid phase (except Buckminster Fullerenes) that I know of and several very different solid phases: graphite (thermodynamically most stable form), diamond, and Buckminster Fullerenes and variations thereof which don't really behave like a solid.\n\nSeveral gaseous elements have no known solids at normal pressure. Iodine has no liquid phase at normal pressure.\n\n\nIn a very general sense, the stronger the attractive forces between the elemental constituents, the more stable the solid/liquid phase. Covalently bonded elements tend to have higher melting points than metals, which in turn tend to have higher melting points than elements occurring in distinct molecules. Quite often the solid and even liquid phases include a change of atomic structure and nature of the bonds. Even in the gaseous phase, sometimes pairing of neutrally charged molecules may occur.
879801
Pentane\n\nIt depends on which compound has the strongest intermolecular forces. In the case of hydrocarbons the intermolecular forces that are present are dispersion forces.\nIn such cases:\n"The more branched a molecule is, the more "spherical" it is, and the smaller surface area it will have - since dispersion forces increase with surface area, the more branched molecules will have a lower boiling point. You may notice that the trend in the melting points is rather different - this is because the longer a branch is, the more potential it has to flop around and disrupt the regular crystalline lattice of frozen pentane, giving a liquid state."
129668
At higher temperatures, the weak intermolecular forces are overcome by the kinetic energy of the molecules, so they break up into solids or gasses. At low temperatures, the molecules have a low enough level of kinetic energy for the weak bonds to hold them together.
675034
Practicalche is essentially right. There's only one thing I would like to add: the kind of interaction between these  molecules arises by induced dipoles (called \nVan der Waals). \nAll kind of chemical attraction is electrostatic, but these molecules have neither positive nor negative densities (because they are "formed" with C and H, very similar in electronegativities).\nThen the attraction is instantaneous and occurs just because in one of the molecules at a certain instant an electronic density forms and as a consequence an opposed density is generated in a neighboring molecule. \nThe capability to form local electronic densities within the molecule depends on its size: the bigger the molecule the easier it is to induce a dipole formation (a positive zone and a negative zone within the molecule).\nSo intermolecular interactions are indeed stronger in bigger molecules.
562669
No, because there is always attraction between the molecules of the two opposite moving bodies. Vanderwaals force or adhesive force.\nThe least friction gives the super liquid Helium two. It does not thematter what the other material is.
275597
because the bond between the molecules of a liquid are weaker  and less, so they can move more freely, and so the liquid takes the shape of it's container, but the ond between the molecules of a solid are more in number and stronger , so they can't move, and they form a dfinite shape.
944411
London dispersion forces are entirely a function of molecular surface area.  Octane has a higher boiling point than methane because its surface area is about seven times larger than that of methane.  We can test this by looking at the boiling temperature of, say, 3-methyl-heptane, which has the same molecular mass as normal octane but is more compact.  The boiling temperature is somewhat lower, which means lower London forces.  Now it is true that the larger the number of bonds, the larger the molecule, so there is an indirect relationship.
569322
Use the ideal gas law \n\nPV/T = constant for the final and initial states.
1021437
a) \n\nThe molecules in a substance are in constant motion. Now there are two oppposing forces on a substance. One is the intermolecular bond energy that tries to keep the molecules together. The other is the kinetic energy of the molecules that tries to push the molecules apart (these two forces work together to keep substances in equilibrium - basically keeps it from exploding or imploding in simple terms).\n\nNow, in solids, the molecules have low kinetic energy but high intermolecular bond energy(IBE). Liquids, the kinetic energy is higher and conversely the IBE is lower. Gases, the kinetic energy is high and the IBE is low (makes sense - the "bond" is weak)\n\nSo now, the kinetic energy or molecules is directly proportional to the heat applied - the hotter it is, the more kinetic energy the molecules have. Therefore when you heat it ... the kintic energy gets stronger and stronger and the IBE gets weaker and weaker until it breaks and the substance undergoes its change of state.\n\nHope this explained it well!
39041
first of all, the experiment has not been done yet, we have not been able to reach absolute zero yet.  gases liquids and solids are properties of atoms and their compounds and have to do with intermolecular forces. in liquids and solids, the atoms are touching(solids they are stuck in place liquids they slide over each other) but regardless, 2 electrons(both being negatively charged) can never touch. that doesnt mean they are a gas, because these phases of matter do not apply to plain electrons. subatomic particles do not experience these phases or phase changes. At absolute zero(which hasnt been reached and thus is still theoretical), all matter would stop moving, so the electrons would stop moving and lose all kinetic energy.
246585
actually gas has the highest coefficient of thermal expansion (cte). Liquid has a very low cte by comparison.\n\nWhy gas? Because electrostatic attaction between gas molecules is insignificant. Their collisions are 100% elastic. Liquid molecules have a stable electrostatic attraction between eachother that has to be overcome to allow evaporation. Its this electrostatic attraction that prevents the liquid molecules from flying appart the same way gas molecules do after collisions.
1055255
the diffusion of liquids and gasses are limited by the cohesive bonds between the composite molecules, and en masse by the forces of gravity in the y axis and friction and cohesion in the x-z plane.  In a gas, the inter-bonding is limited or nil, so each molecule has more degrees of freedom and hence more statistical probability of random scattering, or diffusion.
502816
Particles in solids are usually packed closer together than in a liquid. But in the case of water, the presence of hydrogen bonds holds water molecules apart in an open lattice structure, as in a tetrahedral open lattice. \n\nAs water cools, it contracts and hydrogen bonds are formed in greater quantities. Since hydrogen bonds are long and strong, they space the water molecules so that the volume of water increases, thereby decreasing its density (when water freezes, it expands by 9%)\nThe hydrogen bonds in solid ice hold the molecules together in fixed positions, revealing a large proportion of empty space. Since it has low density, ice shows the unique property of floating. But in liquid water, hydrogen bonds are constantly being made and broken.
658260
A bose-einstein condensate occurs a very low temperatures, about 4K in Helium.  When helium forms a condensate it stops following many physical rules.  For example, a bose-einstein condensate can go up the side of the container that it is in against the force of gravity.  The paulli exclusion principle, one molecule per quantum state, breaks down as well. It is found in very few laboritories, and as of yet has no uses, but it probably will eventually.