Student Exploration: Polarity and Intermolecular Forces

Name: Journey Sheffield Date: 7/7/2026 Student Exploration: Polarity and Intermolecular Forces 50% of Assignment Grade Simulation Portion: Directions: Follow the instructions to go through the simulation. Respond to the questions and prompts in the orange boxes. Vocabulary: dipole, dipole-dipole force, dipole-induced dipole force, electronegativity, intermolecular force, ionic bond, London dispersion force, molecule, nonpolar, nonpolar covalent bond, partial charges, polar, polar covalent bond, valence electron Prior Knowledge Questions (Do these BEFORE using the Gizmo.) 1.​ A big bully is having a tug-of-war with a small child. There is a ball attached to the middle of the rope. Toward whom will the ball move? ​ ​ ​ The ball would go towards the bully 2.​ Two equally strong kids are having a tug-of-war. What do you expect to happen to the ball in this situation? I think the ball would stay in the middle and it would not go towards either child. ​ ​ ​ ​ ​ ​ ​ ​ Gizmo Warm-up Just like in a tug-of-war, atoms that are bonded to one another pull on the electrons they share. In the Polarity and Intermolecular Forces Gizmo, you will explore how these opposing forces relate to bond types and the forces between molecules. To begin, drag the Na (sodium) and Cl (chlorine) atoms into the simulation area. Turn on Show valence electrons. A valence electron is found in the outermost energy level of the atom. 1.​ Click Play ( ). What do you notice? ​ ​ ​ ​ ​ ​ ​ ​ I noticed that the chlorine has a larger pool that surrounds it compared to the sodium ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2.​ Which atom seems to be pulling more on the sodium’s one valence electron? ​ How do you know? ​ ​ Chlorine Seems to be the more electronegative Then the sodium so it will pull on the sodium valence electrons more ​ ​ ​ ​ ​ ​ ​ ​ ​ Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved 3.​ What happens to the colors of the simulated atoms, and what does this indicate? ​ ​ The sodium turned blue which means that it has a positive charge while the chlorine turned red meaning that it has a negative charge Get the Gizmo ready: Activity A: ●​ On the BOND POLARITY tab, click Reset ( ●​ Drag the atoms out of the simulation area. Bond polarity ). Introduction: A neutral atom has the same number of protons as electrons. Atoms that gain electrons become negatively charged, while those that lose electrons become positive. A polar bond forms when shared electrons are pulled closer to one atom than another, causing the bonded atoms to become partially charged. In a nonpolar bond, electrons are shared equally. Question: What causes bonds to be polar or nonpolar? 1.​ Observe: Select the Show polar molecule inset checkbox. The animation shows the probable location of electrons (orange dots) in a polar molecule. A. What do you notice about the distribution of the electrons? I noticed that the electrons in the polar bond are closer to the atom that they are more attracted to B. How does this electron distribution affect the charges of the bonded atoms? The more electrons on the pole means that it will more negative compared to the positive end of the Pole 2.​ Observe: Turn on the Show nonpolar molecule inset. A. How are the electrons in this molecule distributed? The electrons Are distributed evenly between both poles B. Why do the bonded atoms remain neutral? It is because neither atom attracted electrons More than the other so it keeps a neutral and stagnant 3.​ Experiment: Turn off Show polar molecule inset and Show nonpolar molecule inset. Check that Show valence electrons is turned on. Drag the Na and Cl atoms into the simulation area. Click Play. Note the colors. Red indicates a negative charge, while blue indicates a positive charge. A. Does a polar or nonpolar bond form? A Polar bond forms due to all ionic bonds being polar B.​ Try several other metal/nonmetal combinations. What do you notice about the bonds that form? I noticed that all the bonds between Metal/nonmetal are polar bonds ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved​ ​ Ionic bonds are polar bonds that form between metal and nonmetal atoms. In this bond, valence electrons are transferred from a metal to a nonmetal. Drag each of these metal/nonmetal combinations into the Ionic bond bin on the upper right. 4.​ Experiment: Now try forming bonds between different combinations of nonmetals. A. What do you notice? The atoms are attracted to the atoms with the greatest electronegativity value making them slightly negative B. Are all of these bonds polar? Explain. No due to some of the bonds have a EN difference of less than 0.4 making them a nonpolar C. Which nonmetal appears to attract electrons the most? Oxygen appears to attract electrons more ​ ​ 5.​ Experiment: Turn on Show electronegativity. Electronegativity (EN) describes how strongly an atom attracts a pair of shared electrons. The higher the EN value, the greater the tendency of an atom to hold onto electrons in a bond and become negatively charged. Electronegativity difference is found by subtracting the EN value of one atom from another. Choose two nonmetals with a small (or no) EN difference between them. Click Play. What happens to the shared electrons in this bond? ​ ​ ​ ​ ​ ​ In a nonpolar bond between two nonmetals no pole on either side is slightly negative or slightly positive so it stays neutral and the electrons aren't strong enough to attract any particular atoms unlike what a polar bond could When the shared electrons experience the same attraction from each atom, the result is a nonpolar covalent bond. Drag the bonded atoms to the Nonpolar covalent bond bin. 6.​ Experiment: Choose two nonmetals with a large electronegativity difference. Click Play. What happens to the valence electrons in this bond? ​ ​ ​ ​ ​ ​ The valence electrons all gravitate towards the slightly more negative atom ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ A bond in which the electrons are shared unequally is a polar covalent bond. Notice the small δ+ and δ– symbols, which indicate partial charges. Drag the resulting combination to the Polar covalent bond bin. 7.​ Classify: Use the Gizmo to categorize the remaining element combinations as forming either ionic, polar covalent, or nonpolar covalent bonds. List your results below. Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved​ ​ Ionic (EN difference > 1.9) Na2O K2O KCI CaO CaCI2 Polar covalent (EN diff. < 1.9 and > 0.40) Nonpolar covalent (EN difference < 0.40) MgCI2 Activity B: Molecular polarity H2 02 N2 CH4 NCI3 Get the Gizmo ready: ●​ Select the MOLECULAR POLARITY tab. Introduction: Ionic bonds, like those found in NaCl, form crystalline solids. Covalent bonds, on the other hand, usually form discrete molecules. A polar molecule, while neutral overall, has a slight positive charge on one end and a slight negative charge on the other. Question: What determines the polarity of molecules? 1.​ Observe: Notice that the molecules containing polar covalent bonds are grouped together at lower left, and the molecules containing nonpolar covalent bonds are at lower right. Drag the H2O molecule into the simulation area. A.​ Are the individual bonds in this molecule polar or nonpolar? ​ ​ ​ ​ ​ ​ ​ They are polar B.​ Click Turn on electric field. What do you notice? ​ ​ I noticed the oxygen is slightly more negative and is attracted to the positive End of the field while hydrogen is slightly more negative and is attracted to the negative end of the field ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ C.​ The electric field consists of a positively charged plate on one side and a negatively charged plate on the opposite side. Which side of the H2O molecule is attracted to the positive plate, and why do you think this attraction occurs? The side containing oxygen is more attracted to the positive plate. I think the attraction is due to the fact that the oxygen is more electronegative than the hydrogen and is slightly negative causing it to attract positive charges since opposite forces attract. D.​ Click Reverse field. Why does the H2O molecule rotate 180°? ​ ​ ​ The molecule rotates by 180° for oxygen to face the positive side of the plate again. Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved​ ​ A polar molecule, such as H2O, changes its orientation when placed in an electric field. The positive end of the molecule is attracted to the negative plate, while the negative end is attracted to the positive plate. Drag this molecule into the Polar bin. 2.​ Observe: Drag the CH4 molecule into the simulation area. A. Do you think this molecule will rotate in the electric field? Why or why not? I do think this molecule will rotate in the electric field due to the fact that methane is nonpolar B. Turn on the electric field. Is this molecule polar or nonpolar? Methane is nonpolar Drag the CH4 molecule into the appropriate bin. 3.​ Classify: With the Gizmo, test and categorize the remaining molecules. Report your findings. Polar molecules NH3 OC12 CO NC13 Nonpolar molecules CI2 CH4 N2 O2 CCI4 CO2 Did the polarity of any of these molecules surprise you? Explain. ​ ​ ​ ​ I was not surprised by the polarity of any of these molecules as you can guess which ones are nonpolar and polar based on if it's diatomic gas also ​ ​ ​ ​ ​ ​ ​ ​ ​ 4.​ Explain: Drag the CCl4 molecule into the simulation area. ​ ​ ​ A. Does this molecule contain polar or nonpolar bonds? Polar bonds B. Turn on the electric field. Why do you I think this molecule does not rotate in the field due to it think the molecule does not rotate in already contains polar bonds despite being overall polar this field? If a molecule is symmetrical, the effect of the partial charges on either side cancel out. In this case, even though it contains polar bonds, the molecule as a whole may be nonpolar. C. What other nonpolar molecule contains polar bonds? CO2 & CC14 Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved​ ​ ​ ​ ​ 5.​ Challenge: Drag the OCl2 molecule into the simulation area. Turn on Show valence electrons. What do you notice at the very top of the oxygen atom, and how does this feature explain why the molecule is polar? In an OCI2 molecule, The top of the oxygen atom contains two more pair electrons. this gives the oxygen end of the molecule a slightly negative charge and a chlorine and a slightly positive charge . In an OCl2 molecule, the top of the oxygen atom contains two lone pairs of electrons. This gives the oxygen end of the molecule a slight negative charge and the chlorine end a slight positive charge. Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved​ ​ Activity C: Intermolecular forces Get the Gizmo ready: ●​ Select the INTERMOLECULAR FORCES tab. Introduction: The polarity of molecules give rise to the forces that act between them. These intermolecular forces, or IMFs, affect many physical properties including boiling point, solubility, viscosity, and surface tension. Question: How does polarity affect the forces between molecules? 1.​ Observe: Select the Show polar molecules inset checkbox. What do you notice? ​ ​ Each polar molecule is known as a dipole, this attraction ready is between the positive end of the dipole in the negative of the other end of a dipole which is why it's called a dipole-dipole Force ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Each polar molecule is known as a dipole. The attraction between the positive end of one dipole and the negative end of another is called a dipole-dipole force. 2.​ Observe: Turn on the Show nonpolar molecules inset. What do you notice? ​ ​ Even when the molecules are nonpolar the random variations in the distribution of electrons can cause parts of these molecules to become slightly charged and unbalance leads to a very tiny short-lived attraction between molecules called a London dispersion force Even when the molecules are nonpolar, random variations in the distribution of electrons can cause parts of these molecules to become slightly charged. This imbalance leads to very tiny, short-lived attractions between molecules called London dispersion forces. 3.​ Experiment: Turn off Show polar molecule inset and Show nonpolar molecule inset. Drag two H2O molecules into the simulation area, and click Play. Click Pause ( ) when you see a bond form between molecules. Sketch the molecules, partial charges, and the bond between them in the space to the right. ✏️ Why is a hydrogen atom in one H2O molecule attracted to the oxygen atom in an adjacent H2O molecule? Similar charges repel each other while opposite attract which creates an attraction in the example when they adjacent Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved​ ​ Drag the H2O-H2O molecule combination into the correct bin on the right. Which type of intermolecular force causes attraction between H2O molecules? ​ ​ ​ ​ Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved​ ​ 4.​ Experiment: Drag two O2 molecules into the simulation area, but do not click Play yet. A. What force do you expect to see between O2 molecules? We would expect to see London dispersion forces B. Click Play and observe. What do you notice? I observed that the molecules together are nonpolar due to them being temporarily polar when they are adjacent C. Which force causes attraction between O2 molecules? The forces that cause the non-molecular bond are the London dispersion forces 5.​ Classify: Drag out different combinations of molecules in the Gizmo and categorize them. Give at least three examples of molecule combinations for each intermolecular force. Dipole-dipole forces NCI3-OCI2 H2O-OCI2 NCI3-NCI3 London dispersion forces O2-O2 CH4CH4 He-he 6.​ Summarize: Fill in the blanks to summarize the patterns you see. dipole dipole forces arise between polar molecules. london dispersion forces arise between nonpolar molecules. 50% of Assignment Grade Post Lab Quiz: AFTER completing the GIZMO activity and lab above, please complete the five question quiz below the simulation. 1.​ 2.​ 3.​ 4.​ 5.​ 6.​ Scroll down past the simulation. Answer the questions under “Assessment Questions” Click “Check your answers” It will tell you if you got any of the questions wrong and why - read over those explanations. Once you understand where you went wrong, go back and retry the assessment questions. Once you have a 100%: a.​ Option 1: Take a screenshot of your score, completion, with your name in the shot and paste it below. b.​ Option 2: Click the “Print” button and generate a PDF, submit that with this worksheet. If your name, grade, or completion is not in the submission, you will not receive full credit. Reproduction for educational use only. Public sharing or posting prohibited. © 2020 ExploreLearning™ All rights reserved