energy into the system and have a higher potential energy. A comparison is made between the QMRC and the corresponding bond-order reaction coordinates (BORC) derived by applying the Pauling bond-order concept . When they get there, each sodium ion picks up an electron from the electrode to form a sodium atom. The surface might define the energy as a function of one or more coordinates; if there is only one coordinate, the surface is called a potential energy curve or energy profile. bond, triple bond here, you would expect the The help section on this chapter's quiz mentions it as either being "shorter or longer" when comparing two diatomic molecules, but I can't figure out what it's referring to i.e. At T = 0 K (no KE), species will want to be at the lowest possible potential energy, (i.e., at a minimum on the PES). Another question that though the internuclear distance at a particular point is constant yet potential energy keeps on increasing. But one interesting question Between any two minima (valley bottoms) the lowest energy path will pass through a maximum at a. What is "equilibrium bond length"? What does negative potential energy mean in this context since the repulsive energy at r=0 was positive? We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Which of these is the graphs of H2, which is N2, and which is O2? Considering only the effective nuclear charge can be a problem as you jump from one period to another. Direct link to SJTheOne's post Careful, bond energy is d, Posted 2 years ago. completely pulling them apart. just a little bit more, even though they might Direct link to asumesh03's post What is bond order and ho, Posted 2 years ago. The ionic radii are Li+ = 76 pm, Mg+2 = 72 pm, and Cl = 181 pm. b. Posted 3 years ago. Overall, the change is . to repel each other. So if you were to base You could view it as the Accessibility StatementFor more information contact us atinfo@libretexts.orgor check out our status page at https://status.libretexts.org. shell and your nucleus. And this makes sense, why it's stable, because each individual hydrogen Thus, E will be three times larger for the +3/1 ions. Taking a look at this graph, you can see several things: The "equilibrium bond length" - basically another phrase for the distance between atoms where potential energy is at its lowest point. . This diagram represents only a tiny part of the whole sodium chloride crystal; the pattern repeats in this way over countless ions. Sketch a diagram showing the relationship between potential energy and internuclear distance (from r = to r = 0) for the interaction of a bromide ion and a potassium ion to form gaseous KBr. Salt crystals that you buy at the store can range in size from a few tenths of a mm in finely ground table salt to a few mm for coarsely ground salt used in cooking. of electrons being shared in a covalent bond. Accessibility StatementFor more information contact us atinfo@libretexts.orgor check out our status page at https://status.libretexts.org. These float to the top of the melt as molten sodium metal. What do I mean by diatomic molecules? Thus, in the process called electrolysis, sodium and chlorine are produced. And why, why are you having at that point has already reached zero, why is . And I'll give you a hint. Because of long-range interactions in the lattice structure, this energy does not correspond directly to the lattice energy of the crystalline solid. Which will result in the release of more energy: the interaction of a gaseous sodium ion with a gaseous oxide ion or the interaction of a gaseous sodium ion with a gaseous bromide ion? The mechanical energy of the object is conserved, E= K+ U, E = K + U, and the potential energy, with respect to zero at ground level, is U (y) = mgy, U ( y) = m g y, which is a straight line through the origin with slope mg m g. In the graph shown in Figure, the x -axis is the height above the ground y and the y -axis is the object's energy. The distance at which the repulsive forces are exactly balanced by attractive forces is bond length. Direct link to lemonomadic's post I know this is a late res, Posted 2 years ago. Once the necessary points are evaluated on a PES, the points can be classified according to the first and second derivatives of the energy with respect to position, which respectively are the gradient and the curvature. these two things together, you're going to have the positive charges of the nuclei repelling each other, so you're gonna have to two atoms closer together, and it also makes it have Differences between ionic substances will depend on things like: Brittleness is again typical of ionic substances. What is the value of the net potential energy E0 as indicated in the figure in kJ mol 1, for d=d0 at which the electron electron repulsion and the nucleus nucleus repulsion energies are absent? The internuclear distance is 255.3 pm. Electrostatic potential energy Distance between nuclei Show transcribed image text Expert Answer 100% (6 ratings) Hard Is bond energy the same thing as bond enthalpy? and further and further apart, the Coulomb forces between them are going to get weaker and weaker Expert Solution At large distances the energy is zero, meaning no interaction. The best example of this I can think of is something called hapticity in organometallic chemistry. Since protons have charge +1 e, they experience an electric force that tends to push them apart, but at short range the . As mentioned in a previous video. If interested, you can view a video visualization of the 14 lattices by Manuel Moreira Baptista, Figure 4.1.3 Small section of the arrangement of ions in an NaCl crystal. lowest potential energy, is shortest for the diatomic molecule that's made up of the smallest atoms. For ions of opposite charge attraction increases as the charge increases and decreases as the distance between the ions increases. In general, the stronger the bond, the smaller will be the bond length. This is represented in the graph on the right. Protonated molecules have been increasingly detected in the interstellar medium (ISM), and usually astrochemical models fail at reproducing the abundances derived from observational spectra. Graph Between Potential Energy and Internuclear Distance Graphs of potential energy as a function of position are useful in understanding the properties of a chemical bond between two atoms. it the other way around? Direct link to Richard's post Do you mean can two atoms, Posted 9 months ago. Stephen Lower, Professor Emeritus (Simon Fraser U.) The major difference between the curves for the ionic attraction and the neutral atoms is that the force between the ions is much stronger and thus the depth of the well much deeper, We will revisit this app when we talk about bonds that are not ionic. Chlorine gas is produced. maybe this one is nitrogen. you're pulling them apart, as you pull further and And at standard temperature and pressure, there, they would naturally, the distance between the two nuclei would be based on where there is the lowest potential energy. And so this dash right over here, you can view as a pair To study a chemical reaction using the PES as a function of atomic positions, it is necessary to calculate the energy for every atomic arrangement of interest. Let's say all of this is So smaller atoms are, in general, going to have a shorter Because Li+ and F are smaller than Na+ and Cl (see Figure 3.2.7 ), the internuclear distance in LiF is shorter than in NaCl. were to find a pure sample of hydrogen, odds are that the individual The energy as a function of internuclear distance can now be plotted. associated with each other, if they weren't interacting The closer the atoms are together, the higher the bond energy. Explain why the energy of the system increases as the distance between the ions decreases from r = r0 to r = 0. Direct link to Tanzz's post At 5:20, Sal says, "You'r, Posted a year ago. The Morse potential U (r) D e. 1 e . r R e 2 . pretty high potential energy. So basically a small atom like hydrogen has a small intermolecular distance because the orbital it is using to bond is small. And actually, let me now give units. zero potential energy. they attract when they're far apart because the electrons of one is attraction to the nucleus (protons) of the other atom. The distinguishing feature of these lattices is that they are space filling, there are no voids. Potential Energy vs Internuclear Distance 7,536 views Sep 30, 2019 207 Dislike Share Save Old School Chemistry 5.06K subscribers Graphic of internuclear distance and discussion of bond. just going to come back to, they're going to accelerate The amount of energy needed to separate a gaseous ion pair is its bond energy. of Wikipedia (Credit: Aimnature). This energy of a system of two atoms depends on the distance between them. temperature, pressure, the distance between The low point in potential energy is what you would typically observe that diatomic molecule's This should make perfect sense: the spring is stretched to the right, so it pulls left in an attempt to return to equilibrium. When it melts, at a very high temperature of course, the sodium and chloride ions can move freely when a voltage is placed across the liquid. The minimum potential energy occurs at an internuclear distance of 75pm, which corresponds to the length of the stable bond that forms between the two atoms. So that's one hydrogen atom, and that is another hydrogen atom. How does the strength of the electrostatic interactions change as the size of the ions increases? [/latex] This is true for any (positive) value of E because the potential energy is unbounded with respect to x. Because we want to establish the basics about ionic bonding and not get involved in detail we will continue to use table salt, NaCl, to discuss ionic bonding. Thus the potential energy is denoted as:- V=mgh This shows that the potential energy is directly proportional to the height of the object above the ground. A PES is a conceptual tool for aiding the analysis of molecular geometry and chemical reaction dynamics. The power source (the battery or whatever) moves electrons along the wire in the external circuit so that the number of electrons is the same. Methods of calculating the energy of a particular atomic arrangement of atoms are well described in the computational chemistry article, and the emphasis here will be on finding approximations of \((V(r)\) to yield fine-grained energy-position information. A diatomic molecule can be represented using a potential energy curve, which graphs potential energy versus the distance between the two atoms (called the internuclear distance). Like, if the nucleus of the atom has a higher nuclear charge, then they repel each other more, and so less likely to get closer, so the optimal diatomic distance is longer. If diatomic nitrogen has triple bond and small radius why it's not smaller than diatomic hydrogen? Well, it'd be the energy of As you go from top to bottom along a group then the number of electron shells increases meaning the valance electrons occupy a greater distance from the nucleus leading to a larger atom. Direct link to Richard's post So a few points here molecular hydrogen, or H2, which is just two hydrogens { "Chapter_4.0:_What_is_a_Chemical_Bond" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Chapter_4.1:_Ionic_Bonding" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Chapter_4.2:_Lattice_Energies_in_Ionic_Solids" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Chapter_4.3:_Chemical_Formulas" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Chapter_4.4:_Naming_Ionic_Compounds" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Chapter_4.5:_End_of_Chapter_Material" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, { "Chapter_4:_Ionic_Bonding" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Chapter_5:_Covalent_Bonding" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()", "Chapter_6:_Molecular_Geometry" : "property get [Map MindTouch.Deki.Logic.ExtensionProcessorQueryProvider+<>c__DisplayClass228_0.b__1]()" }, [ "article:topic", "hypothesis:yes", "showtoc:yes", "license:ccbyncsa", "authorname:anonymous", "licenseversion:40" ], https://chem.libretexts.org/@app/auth/3/login?returnto=https%3A%2F%2Fchem.libretexts.org%2FCourses%2FHoward_University%2FGeneral_Chemistry%253A_An_Atoms_First_Approach%2FUnit_2%253A__Molecular_Structure%2FChapter_4%253A_Ionic_Bonding%2FChapter_4.1%253A_Ionic_Bonding, \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}}}\) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\), Chapter 4.2: Lattice Energies in Ionic Solids, Sodium chloride has a high melting and boiling point, The electrical behavior of sodium chloride, status page at https://status.libretexts.org. Calculation of the Morse potential anharmonicity constant The Morse potential is a relatively simple function that is used to model the potential energy of a diatomic molecule as a function of internuclear distance. Direct link to blitz's post Considering only the effe, Posted 2 months ago. Potential energy is stored energy within an object. It might be helpful to review previous videos, like this one covering bond length and bond energy. good candidate for O2. Final Exam Study Guide. will call the bond energy, the energy required to separate the atoms. - [Instructor] If you However, in General Relativity, energy, of any kind, produces gravitational field. This creates a smooth energy landscape and chemistry can be viewed from a topology perspective (of particles evolving over "valleys""and passes"). becomes zero for a certain inter-molecular distance? From the graph shown, Y2 = N2, X2 = O2, Z2 = H2. tried to pull them apart? And so it would be this energy. Why? The internuclear distance in the gas phase is 175 pm. what is the difference between potential and kinetic energy. So that's one hydrogen there. 7. Ionic substances all have high melting and boiling points. The energy minimum energy Table of Contents Creative Commons Attribution/Non-Commercial/Share-Alike. A graph of potential energy versus the distance between atoms is a useful tool for understanding the interactions between atoms. internuclear distance to be at standard Why do the atoms attract when they're far apart, then start repelling when they're near? Describe one type of interaction that destabilizes ionic compounds. Direct link to Tzviofen 's post So what is the distance b, Posted 2 years ago. And so to get these two atoms to be closer and closer What is the value of the net potential energy E 0 (as indicated in the figure) in kJ mol 1, for d = d 0 at which the electron-electron repulsion and the nucleus-nucleus repulsion energies are absent? Consequently, in accordance with Equation 4.1.1, much more energy is released when 1 mol of gaseous Li+F ion pairs is formed (891 kJ/mol) than when 1 mol of gaseous Na+Cl ion pairs is formed (589 kJ/mol). And so that's actually the point at which most chemists or physicists or scientists would label What is the relationship between the strength of the electrostatic attraction between oppositely charged ions and the distance between the ions? The energy of a system made up of two atoms depends on the distance between their nuclei. Direct link to Richard's post Potential energy is store, Posted a year ago. In NaCl, of course, an electron is transferred from each sodium atom to a chlorine atom leaving Na+ and Cl-. In solid sodium chloride, of course, that ion movement can not happen and that stops any possibility of any current flow in the circuit. What happens at the point when P.E. separate atoms floating around, that many of them, and It turns out, at standard I'll just think in very Typically the 12-6 Lennard-Jones parameters (n =12, m =6) are used to model the Van der Waals' forces 1 experienced between two instantaneous dipoles.However, the 12-10 form of this expression (n =12, m =10) can be used to model . For the interaction of a sodium ion with an oxide ion, Q1 = +1 and Q2 = 2, whereas for the interaction of a sodium ion with a bromide ion, Q1 = +1 and Q2 = 1. where is the potential well depth, is the distance where the potential equals zero (also double the Van-der-Waals radius of the atom), and R min is the distance where the potential reaches a minimum, i.e. Direct link to comet4esther's post How do you know if the di, Posted 3 years ago. Answer: 3180 kJ/mol = 3.18 103 kJ/mol. Potential, Kinetic, and Total Energy for a System. One is for a pair of potassium and chloride ions, and the other is for a pair of potassium and fluoride ions. What if we want to squeeze Now let us calculate the change in the mean potential energy. The bond energy \(E\) has half the magnitude of the fall in potential energy. Inserting the values for Li+F into Equation 4.1.1 (where Q1 = +1, Q2 = 1, and r = 156 pm), we find that the energy associated with the formation of a single pair of Li+F ions is, \( E = k\dfrac{Q_{1}Q_{2}}{r_{0}} = (2.31 \times {10^{ - 28}}\rm{J}\cdot \cancel{m}) \left( \dfrac{( + 1)( - 1)}{156\; \cancel{pm} \times 10^{ - 12} \cancel{m/pm}} \right) = - 1.48 \times 10^{ - 18}\; J/ion\; pair \), Then the energy released per mole of Li+F ion pairs is, \( E=\left ( -1.48 \times 10^{ - 18}\; J/ \cancel{ion pair} \right )\left ( 6.022 \times 10^{ 23}\; \cancel{ion\; pair}/mol\right )=-891\; kJ/mol \) . A critical analysis of the potential energy curve helps better understand the properties of the material. Now, potential energy, The PES is the energy of a molecule as a function of the positions of its nuclei \(r\). Kinetic energy is energy an object has due to motion. So the higher order the bond, that will also bring the is a little bit shorter, maybe that one is oxygen, and The potential energy function for diatomic molecule is U (x)= a x12 b x6. Diatomic hydrogen, you just So far so good. The internuclear distance at which the potential energy minimum occurs defines the bond length. Direct link to Richard's post Yeah you're correct, Sal . essentially going to be the potential energy if these two The purple curve in Figure 4.1.2 shows that the total energy of the system reaches a minimum at r0, the point where the electrostatic repulsions and attractions are exactly balanced. The closer the atoms come to each other, the lower the potential energy. The energy of the system reaches a minimum at a particular internuclear distance (the bond distance). Several factors contribute to the stability of ionic compounds. Coulomb forces are increasing between that outermost And so with that said, pause the video, and try to figure it out. Direct link to Richard's post Well picometers isn't a u, Posted 2 years ago. Given \(r\), the energy as a function of the positions, \(V(r)\), is the value of \(V(r)\) for all values of \(r\) of interest. Hazleton Area School District Student Management. expect your atomic radius to get a little bit smaller. because that is a minimum point. diatomic molecule or N2. These then pair up to make chlorine molecules. So that makes sense over Why pot. around the internuclear line the orbital still looks the same. Figure 4.1.2 A Plot of Potential Energy versus Internuclear Distance for the Interaction between Ions With Different Charges: A Gaseous Na+ Ion and a Gaseous Cl Ion The energy of the system reaches a minimum at a particular distance (r0) when the attractive and repulsive interactions are balanced. 1 CHE101 - Summary Chemistry: The Central Science. Calculate the amount of energy released when 1 mol of gaseous Li+F ion pairs is formed from the separated ions. Conventionally, potential-energy curves are fit by the simple Morse functions, (ln2) although it has long been realized that this function often gives a poor fit at internuclear distances somewhat greater than the equilibrium distance. Find Your Next Great Science Fair Project! Graphed below is the potential energy of a spring-mass system vs. deformation amount of the spring. So in the vertical axis, this is going to be potential energy, potential energy. Rigoro. If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked. No electronegativity doesnt matter here, the molecule has two oxygen atoms bonded together, they have the same electronegativity. Figure 4.1.5 Cleaving an ionic crystal. The Dimensionality of a Potential Energy Surface, To define an atoms location in 3-dimensional space requires three coordinates (e.g., \(x\), \(y\),and \(z\) or \(r\), \(\theta\) and \(phi\) in Cartesian and Spherical coordinates) or degrees of freedom. But as you go to the right on a row, your radius decreases.". Why did he give the potential energy as -432 kJ/mol, and then say to pull apart a single diatomic molecule would require 432 kJ of energy? high of a potential energy, but this is still going to be higher than if you're at this stable point. Login ID: Password: The new electrons deposited on the anode are pumped off around the external circuit by the power source, eventually ending up on the cathode where they will be transferred to sodium ions. And if you go really far, it's going to asymptote The bond length is the internuclear distance at which the lowest potential energy is achieved. Potential energy curves govern the properties of materials. However, the large negative value indicates that bringing positive and negative ions together is energetically very favorable, whether an ion pair or a crystalline lattice is formed. A graph of potential energy versus internuclear distance for two Cl atoms is given below. It is helpful to use the analogy of a landscape: for a system with two degrees of freedom (e.g. The positive sodium ions move towards the negatively charged electrode (the cathode). And that's what people And so what we've drawn here, Given: cation and anion, amount, and internuclear distance, Asked for: energy released from formation of gaseous ion pairs. Figure 9.6.1: A potential Energy Curve for a covalent bond. An approximation to the potential energy in the vicinity of the equilibrium spacing is. Because Hydrogen has the smallest atomic radius I'm assuming it has the highest effective nuclear charge here pulling on its outer electrons hence why is Hydrogens bonding energy so low shouldn't it be higher than oxygen considering the lack of electron shielding? The LibreTexts libraries arePowered by NICE CXone Expertand are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. But then when you look at the other two, something interesting happens. Direct link to jtbooth00's post Why did he give the poten, Posted a year ago. why is julie sommars in a wheelchair. The attractive energy E a and the repulsive energy energy E r of an Na + Cl - pair depends on the inter-atomic distance, r according to the following equations: E a = 1.436 r E r = 7.32 10 6 r 8 The total bond energy, E n is the sum of the attractive energy term E a and the repulsive energy term E r: E n = E a + E r The LibreTexts libraries arePowered by NICE CXone Expertand are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. one right over here. it is a double bond. The potential energy function for the force between two atoms in a diatomic molecule which is approximately given as, U (x)= a x12 b x6. I know this is a late response, but from what I gather we can tell what the bond order is by looking at the number of valence electrons and how many electrons the atoms need to share to complete their outer shell. We can thus write the Schrodinger equation for vibration h2 2 d2 dR2 +V(R) (R) = E(R) (15) If you're seeing this message, it means we're having trouble loading external resources on our website. A potential energy surface (PES) describes the potential energy of a system, especially a collection of atoms, in terms of certain parameters, normally the positions of the atoms. When atoms of elements are at a large distance from each other, the potential energy of the system is high. At that point the two pieces repel each other, shattering the crystal. And this distance right over here is going to be a function of two things. The graph of potential energy of a pair of nucleons as a function of their separation shows a minimum potential energy at a value r (approx. \n \n Below the radial distance at which the system has its minimal energy, the force becomes repulsive, and one would have to expend energy to push the two atoms closer together. where m and n are integers, and C n and C m are constants whose values depend on the depth of the energy well and the equilibrium separation of the two atoms' nuclei. And it turns out that Using the landscape analogy from the introduction, \(V(r)\) gives the height on the "energy landscape" so that the concept of a potential energy surface arises. At very short distances, repulsive electronelectron interactions between electrons on adjacent ions become stronger than the attractive interactions between ions with opposite charges, as shown by the red curve in the upper half of Figure 4.1.2. The height of the potential energy curve is the potential energy of the object, and the distance between the potential energy curve and the total energy line is the kinetic energy of the object. I'm not even going to label this axis yet. Molecular and ionic compound structure and properties, https://www.khanacademy.org/science/ap-chemistry-beta/x2eef969c74e0d802:molecular-and-ionic-compound-structure-and-properties/x2eef969c74e0d802:intramolecular-force-and-potential-energy/v/bond-length-and-bond-energy, Creative Commons Attribution/Non-Commercial/Share-Alike. The sodium ion in the center is being touched by 6 chloride ions as indicated by the blue lines. Direct link to Taimas's post If diatomic nitrogen has , Posted 9 months ago. This is the energy released when 1 mol of gaseous ion pairs is formed, not when 1 mol of positive and negative ions condenses to form a crystalline lattice. Our convention is that if a chemcal process provides energy to the outside world, the energy change is negative. February 27, 2023 By scottish gaelic translator By scottish gaelic translator This molecule's only made up of hydrogen, but it's two atoms of hydrogen. What is the electrostatic attractive energy (E, in kilojoules) for 130 g of gaseous HgI2? This stable point is stable distance between the nuclei. energy into the system and have a higher potential energy. Intramolecular force and potential energy. 6. Figure 3-4(a) shows the energies of b and * as a function of the internuclear separation. The nuclear force (or nucleon-nucleon interaction, residual strong force, or, historically, strong nuclear force) is a force that acts between the protons and neutrons of atoms.Neutrons and protons, both nucleons, are affected by the nuclear force almost identically. The relation has the form V = D e [1exp(nr 2 /2r)][1+af(r)], where the parameter n is defined by the equation n = k e r e /D e.For large values of r, the f(r) term assumes the form of a LennardJones (612) repulsive . The bond length is the internuclear distance at which the lowest potential energy is achieved. towards some value, and that value's Because as you get further Direct link to Frank Wang's post "your radius for an atom , Posted 2 months ago.