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General Chemistry Group 6.10283639_1171172
- 1. GROUP 6 Intermolecular forces ofLiquids and Solids
- 2. Kinetic molecular model ofliquids and solids 2. Intermolecular Forces 3. Dipole-dipole forces 4. Ion-dipole forces 5. Dispersion forces 6. Hydrogen bonds 7.Properties of liquids and IMF 8. Surface Tension 1.Kinetic molecular model of liquids and solids 2. Intermolecular Forces 3. Dipole-dipole forces 4. Ion-dipole forces 5. Dispersion forces 6. Hydrogen bonds 7.Properties of liquids and IMF 8. Surface Tension 9. Viscosity 10. Vapour pressure, boiling point 11. Crystalline and amorphous solids 12. Types of Crystals - ionic, covalent, molecular, metallic
- 3. KINETIC MOLECULAR MODELOF LIQUIDS AND SOLIDS KINETIC MOLECULAR MODEL OF LIQUIDS AND SOLIDS The kinetic molecular model of liquids and solids is a theory that describes the behavior of particles in these states of matter.
- 4. KINETIC MOLECULAR MODELOF LIQUIDS AND SOLIDS KINETIC MOLECULAR MODEL OF LIQUIDS AND SOLIDS Liquids: ●Particles in liquids are close together but still have enough energy to move around. ●They constantly slide past each other, allowing liquids to flow and take the shape of their container. ●The attractive forces between particles keep them close together but not in fixed positions.
- 5. KINETIC MOLECULAR MODELOF LIQUIDS AND SOLIDS KINETIC MOLECULAR MODEL OF LIQUIDS AND SOLIDS Solids: ●Particles in solids are tightly packed and have very little freedom to move. ●They vibrate in fixed positions due to their low energy levels. ●The attractive forces between particles are strong enough to hold them in a fixed arrangement, giving solids a definite shape and volume.
- 6. Intermolecular forces arethe attractive forces that exist between molecules. These forces play a crucial role in determining the physical properties of substances, such as boiling point, melting point, and solubility. INTERMOLECULAR FORCES Intermolecular forces are forces of attraction or repulsion which act between neighboring particles (atoms, molecules or ions). They are weak compared to the intramolecular forces, which keep a molecule together (e.g., covalent and ionic bonding)
- 7. KINETIC MOLECULAR MODELOF LIQUIDS AND SOLIDS KINETIC MOLECULAR MODEL OF LIQUIDS AND SOLIDS The kinetic molecular model helps us understand the physical properties of liquids and solids, such as their density, melting point, and boiling point. It also explains phenomena like diffusion, where particles spread out to fill the available space.
- 8. Boiling Point: Theboiling point of a substance is the temperature at which it changes from a liquid to a gas. The strength of intermolecular forces affects the boiling point. Substances with stronger intermolecular forces require more energy to break the attractive forces between molecules, resulting in higher boiling points. The physical properties of substances INTERMOLECULAR FORCES • Boiling Point: The boiling point of a substance is the temperature at which it changes from a liquid to a gas. The strength of intermolecular forces affects the boiling point. Substances with stronger intermolecular forces require more energy to break the attractive forces between molecules, resulting in higher boiling points.
- 9. Boiling Point: Theboiling point of a substance is the temperature at which it changes from a liquid to a gas. The strength of intermolecular forces affects the boiling point. Substances with stronger intermolecular forces require more energy to break the attractive forces between molecules, resulting in higher boiling points. The physical properties of substances INTERMOLECULAR FORCES ●Melting Point: The melting point of a substance is the temperature at which it changes from a solid to a liquid. Intermolecular forces also influence the melting point. Substances with stronger intermolecular forces have higher melting points because more energy is required to overcome the attractive forces between molecules and change the substance's solid structure into a liquid.
- 10. ● Solubility: Intermolecularforces play a significant role in the solubility of substances. Like dissolves like, meaning substances with similar intermolecular forces tend to dissolve in each other. Polar substances dissolve in polar solvents through dipole-dipole interactions, while nonpolar substances dissolve in nonpolar solvents through dispersion forces. The strength and type of intermolecular forces between the solute and solvent determine the solubility of a substance. The physical properties of substances INTERMOLECULAR FORCES ●Solubility: Intermolecular forces play a significant role in the solubility of substances. Like dissolves like, meaning substances with similar intermolecular forces tend to dissolve in each other. Polar substances dissolve in polar solvents through dipole-dipole interactions, while nonpolar substances dissolve in nonpolar solvents through dispersion forces. The strength and type of intermolecular forces between the solute and solvent determine the solubility of a substance.
- 11. Intermolecular forces arethe attractive forces that exist between molecules. These forces play a crucial role in determining the physical properties of substances, such as boiling point, melting point, and solubility. Intermolecular Forces Dipole-dipole Forces Ion-dipole Forces Dispersion Forces Hydrogen Bonds
- 12. Dispersion Forces (LondonForces): ● Dispersion forces are the weakest type of intermolecular force. ● They occur in all molecules, whether they are polar or nonpolar. ● These forces arise from temporary fluctuations in electron distribution, creating temporary dipoles. ● The strength of dispersion forces increases with the size and shape of the molecule. ● Larger molecules or those with more surface area tend to have stronger dispersion forces. TYPES OF INTERMOLICULAR FORCES Dipole-Dipole Interactions: ●Dipole-dipole interactions occur between polar molecules. ●A polar molecule has a positive end and a negative end, known as a dipole. ●The positive end of one molecule is attracted to the negative end of another molecule, creating an intermolecular force. ●The strength of dipole-dipole interactions depends on the magnitude of the dipole moment. ●Substances with stronger dipole-dipole interactions tend to have higher boiling points and higher melting points.
- 13. Dipole-Dipole Forces Dipole-dipole interactionsoccur between polar molecules. They involve the attraction between the positive end of one molecule and the negative end of another molecule. This creates an intermolecular force known as a dipole- dipole force. Examples of polar molecules that experience dipole-dipole interactions include hydrogen chloride (HCl).
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- 18. Dispersion Forces (LondonForces): ● Dispersion forces are the weakest type of intermolecular force. ● They occur in all molecules, whether they are polar or nonpolar. ● These forces arise from temporary fluctuations in electron distribution, creating temporary dipoles. ● The strength of dispersion forces increases with the size and shape of the molecule. ● Larger molecules or those with more surface area tend to have stronger dispersion forces. TYPES OF INTERMOLICULAR FORCES Hydrogen Bonding: ●Hydrogen bonding is a special type of dipole-dipole interaction. ●It occurs when hydrogen is bonded to a highly electronegative atom (such as nitrogen, oxygen, or fluorine) and is attracted to another electronegative atom in a different molecule. ●Hydrogen bonding is stronger than regular dipole-dipole interactions. ●It plays a significant role in the unique properties of substances like water, ammonia, and alcohols. ●Substances with hydrogen bonding tend to have higher boiling points, higher melting points, and unique solubility properties.
- 20. Ion-dipole forces Ion-dipole forcesoccur when an ion, which is a charged particle, interacts with a polar molecule. The charged ion is attracted to the opposite charge on the polar molecule, creating an ion-dipole force.
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- 22. Dispersion Forces (LondonForces): ● Dispersion forces are the weakest type of intermolecular force. ● They occur in all molecules, whether they are polar or nonpolar. ● These forces arise from temporary fluctuations in electron distribution, creating temporary dipoles. ● The strength of dispersion forces increases with the size and shape of the molecule. ● Larger molecules or those with more surface area tend to have stronger dispersion forces. TYPES OF INTERMOLICULAR FORCES Dispersion Forces (London Forces): ●Dispersion forces are the weakest type of intermolecular force. ●Also known as London dispersion forces or van der Waals forces ●They occur in all molecules, whether they are polar or nonpolar. ●These forces arise from temporary fluctuations in electron distribution, creating temporary dipoles. ●The strength of dispersion forces increases with the size and shape of the molecule. ●Larger molecules or those with more surface area tend to have stronger dispersion forces.
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- 24. Properties of Liquids Liquids -Denserthan gases -Have a definite volume -Attractive forces not strong enough to keep molecules from moving allowing liquids to hold shape of container
- 25. Properties of Liquids Fluidity:Liquids are fluid and can flow easily, unlike solids that have a fixed shape. The particles in a liquid can move past each other, allowing the liquid to take the shape of its container. Density: Liquids have a relatively high density compared to gases but lower density than solids. The particles in a liquid are closely packed together, but they have more space between them compared to solids.
- 26. Properties of Liquids Incompressibility:Liquids are generally considered to be incompressible, meaning their volume does not change significantly when subjected to pressure. Unlike gases, which can be compressed, the particles in a liquid are already close together, limiting their ability to be compressed further.
- 27. Properties of Liquids SurfaceTension: Liquids have surface tension, which is the tendency of the surface of a liquid to minimize its surface area. This is due to the cohesive forces between the liquid particles. Surface tension allows some insects, like water striders, to walk on water.
- 28. Properties of Liquids Viscosity:Viscosity is a measure of a liquid's resistance to flow. Liquids with high viscosity, like honey or syrup, flow slowly, while liquids with low viscosity, like water, flow more easily. Viscosity depends on the strength of intermolecular forces and the size and shape of the liquid particles.
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- 30. Vapour pressure The vaporpressure of a liquid lowers the amount of pressure exerted on the liquid by the atmosphere. As a result, liquids with high vapor pressures have lower boiling points. Vapor pressure can be increased by heating a liquid and causing more molecules to enter the atmosphere.
- 31. Boiling will occurwhen the vapor pressure is equal to the atmospheric pressure. This is called the boiling point. Boiling Point Boiling will occur when the vapor pressure is equal to the atmospheric pressure. This is called the boiling point.
- 32. Boiling Point andFreezing Point Cohesion is intermolecular forces between like molecules; this is why water molecules are able to hold themselves together in a drop. Water molecules are very cohesive because of the molecule's polarity. This is why you can fill a glass of water just barely above the rim without it spilling. Cohesion
- 33. When freezing, moleculeswithin water begin to move around more slowly, making it easier for them to form hydrogen bonds and eventually arrange themselves into an open crystalline, hexagonal structure. Because of this open structure as the water molecules are being held further apart, the volume of water increases about 9%. So molecules are more tightly packed in water's liquid state than its solid state. This is why a can of soda can explode in the freezer. Types of Solid States Based on the arrangement of constituent particles, solids are classified into two-state types: -Crystalline Solids -Amorphous Solids
- 34. When freezing, moleculeswithin water begin to move around more slowly, making it easier for them to form hydrogen bonds and eventually arrange themselves into an open crystalline, hexagonal structure. Because of this open structure as the water molecules are being held further apart, the volume of water increases about 9%. So molecules are more tightly packed in water's liquid state than its solid state. This is why a can of soda can explode in the freezer. Crystalline Solid State Crystalline solids are those that have a typical geometry. In such types of solids, there are definite arrangements of particles (atoms, molecules or ions ) throughout the 3-dimensional network of a crystal in a long-range order. Examples include Sodium Chloride, Quartz, Diamond, etc.
- 35. Properties of CrystallineSolids Crystalline solids have a sharp melting point and start melting when it reaches a particular temperature. The shape of crystalline solids is definite and has typical arrangements of particles. They show cleavage property, i.e., when they are cut with the edge of a sharp tool, they split into two pieces, and the newly generated surfaces are smooth and plain. They have definite heat of fusion (amount of energy needed to melt a given mass of solid at its melting point). Crystalline solids are anisotropic, which means their physical properties, like electrical resistance or refractive index, show different values when they are measured along with different directions in the same crystal. Crystalline solids are true solids. Properties of Crystalline Solids 1. Crystalline solids have a sharp melting point and start melting when it reaches a particular temperature. 2. The shape of crystalline solids is definite and has typical arrangements of particles. 3. They show cleavage property, i.e., when they are cut with the edge of a sharp tool, they split into two pieces, and the newly generated surfaces are smooth and plain.
- 36. When freezing, moleculeswithin water begin to move around more slowly, making it easier for them to form hydrogen bonds and eventually arrange themselves into an open crystalline, hexagonal structure. Because of this open structure as the water molecules are being held further apart, the volume of water increases about 9%. So molecules are more tightly packed in water's liquid state than its solid state. This is why a can of soda can explode in the freezer. 4.They have definite heat of fusion (amount of energy needed to melt a given mass of solid at its melting point). 5. Crystalline solids are anisotropic, which means their physical properties, like electrical resistance or refractive index, show different values when they are measured along with different directions in the same crystal. 6. Crystalline solids are true solids. Properties of Crystalline Solids
- 37. When freezing, moleculeswithin water begin to move around more slowly, making it easier for them to form hydrogen bonds and eventually arrange themselves into an open crystalline, hexagonal structure. Because of this open structure as the water molecules are being held further apart, the volume of water increases about 9%. So molecules are more tightly packed in water's liquid state than its solid state. This is why a can of soda can explode in the freezer. Types of Crystalline Solids On the basis of the nature of intermolecular forces or chemical bonding, crystalline solids are further classified into four categories. They are as follows: -Molecular solids -Ionic solids -Metallic solids -Covalent solids
- 38. When freezing, moleculeswithin water begin to move around more slowly, making it easier for them to form hydrogen bonds and eventually arrange themselves into an open crystalline, hexagonal structure. Because of this open structure as the water molecules are being held further apart, the volume of water increases about 9%. So molecules are more tightly packed in water's liquid state than its solid state. This is why a can of soda can explode in the freezer. Molecular Solids In molecular solids, the constituent particles are molecules. They are further divided into three categories: 1. Non-polar Molecular Solids These solids are formed from molecules or atoms that share a non-polar covalent bond. The atoms or molecules are held by weak dispersion force or by London forces.
- 39. When freezing, moleculeswithin water begin to move around more slowly, making it easier for them to form hydrogen bonds and eventually arrange themselves into an open crystalline, hexagonal structure. Because of this open structure as the water molecules are being held further apart, the volume of water increases about 9%. So molecules are more tightly packed in water's liquid state than its solid state. This is why a can of soda can explode in the freezer. Non-polar Molecular Solids 1. The physical nature of non-polar solids is soft. 2. They don’t conduct electricity, so they are insulators. 3. They have a very low melting point. 4. Examples: H2, Cl2, I2 etc.
- 40. When freezing, moleculeswithin water begin to move around more slowly, making it easier for them to form hydrogen bonds and eventually arrange themselves into an open crystalline, hexagonal structure. Because of this open structure as the water molecules are being held further apart, the volume of water increases about 9%. So molecules are more tightly packed in water's liquid state than its solid state. This is why a can of soda can explode in the freezer. Molecular Solids Polar Molecular Solids These solids are held together by polar covalent bonds, and the atoms/molecules are bonded by relatively stronger dipole- dipole interactions. The physical nature is soft, and most of these are gases or liquids at room temperature.
- 41. When freezing, moleculeswithin water begin to move around more slowly, making it easier for them to form hydrogen bonds and eventually arrange themselves into an open crystalline, hexagonal structure. Because of this open structure as the water molecules are being held further apart, the volume of water increases about 9%. So molecules are more tightly packed in water's liquid state than its solid state. This is why a can of soda can explode in the freezer. Types of Crystalline Solids Polar Molecular Solids They do not conduct electricity, and they have a higher melting point than non-polar molecular solids. Examples: HCl, SO2, NH3, etc.
- 42. When freezing, moleculeswithin water begin to move around more slowly, making it easier for them to form hydrogen bonds and eventually arrange themselves into an open crystalline, hexagonal structure. Because of this open structure as the water molecules are being held further apart, the volume of water increases about 9%. So molecules are more tightly packed in water's liquid state than its solid state. This is why a can of soda can explode in the freezer. Molecualar Solids Hydrogen-bonded Molecular Solids The solids contain polar covalent bonds with Hydrogen, Fluorine, Oxygen and Nitrogen atoms. In these solids, molecules are held together via strong hydrogen bonding.
- 43. When freezing, moleculeswithin water begin to move around more slowly, making it easier for them to form hydrogen bonds and eventually arrange themselves into an open crystalline, hexagonal structure. Because of this open structure as the water molecules are being held further apart, the volume of water increases about 9%. So molecules are more tightly packed in water's liquid state than its solid state. This is why a can of soda can explode in the freezer. The physical nature of such solids is hard. They do not conduct electricity. The physical state of these solids is volatile liquids or soft solids under room temperature. They have a low melting point. Example: H2O (Ice ).
- 44. When freezing, moleculeswithin water begin to move around more slowly, making it easier for them to form hydrogen bonds and eventually arrange themselves into an open crystalline, hexagonal structure. Because of this open structure as the water molecules are being held further apart, the volume of water increases about 9%. So molecules are more tightly packed in water's liquid state than its solid state. This is why a can of soda can explode in the freezer. Ionic Solids In ionic solids, the constituent particles are ions. These are formed by the arrangement of cations and anions by strong Coulombic forces. -These are hard and brittle in nature. Ionic solids act as an insulator in a solid-state but are conductors in a molten and aqueous state. -They have a high melting point. Examples: NaCl, MgO, ZnS, CaF2 etc
- 45. When freezing, moleculeswithin water begin to move around more slowly, making it easier for them to form hydrogen bonds and eventually arrange themselves into an open crystalline, hexagonal structure. Because of this open structure as the water molecules are being held further apart, the volume of water increases about 9%. So molecules are more tightly packed in water's liquid state than its solid state. This is why a can of soda can explode in the freezer. -These are hard and brittle in nature. Ionic solids act as an insulator in a solid-state but are conductors in a molten and aqueous state. -They have a high melting point. Examples: NaCl, MgO, ZnS, CaF2 etc Ionic Solids
- 46. Metallic Solids -Positive metalions in a sea of delocalized electrons. These electrons are evenly spread out throughout the crystal. -Due to the presence of free and mobile electrons, they are responsible for high electrical and thermal conductivity.
- 47. -They are conductorsin both solid and molten states. -The physical nature of these solids is hard, but they are malleable and ductile. -They have high melting point than ionic solids. Examples: Fe, Cu, Ag, Mg, etc. Metallic Solids
- 48. Covalent or NetworkSolids A wide range of crystalline solids of non-metal form covalent bonds between adjacent atoms throughout the crystal and form giant molecules or large molecules.
- 49. Covalent or NetworkSolids -These solids are hard, like diamond and soft, like graphite which are isotopes of carbon. -They are insulators, as in the case of a diamond, but in the case of graphite, due to free electrons, they conduct electricity and act as a conductor.
- 50. Types of Solids AmorphousSolid State Amorphous solid-state comprises those solids which have the property of rigidity and incompressibility but to a certain extent. They do not have a definite geometrical form or long range of order. Examples include glass, rubber, plastic, etc.
- 51. Properties of AmorphousSolids -Amorphous solids are gradually softened over a range of temperatures, and they can be moulded into different shapes on heating. -Amorphous solids are pseudo-solids or supercooled liquids, which means they have a tendency to flow very slowly. If you observe the glass pans, which are fixed to windows of old buildings, they are found to be slightly thicker from the bottom than at the top.
- 52. Properties of AmorphousSolids -Amorphous solids have irregular shapes. i.e., their constituent particles do not have definite geometry of arrangements. -When amorphous solids are cut with a sharp edge tool, they form pieces with irregular surfaces.
- 53. Properties of AmorphousSolids -Amorphous solids do not have definite heat of fusion due to the irregular arrangement of the particles. -Amorphous solids are isotropic in nature, which means the value of any physical property would be the same along any direction because of the irregular arrangement of particles.
- 54. . Amorphous Solids Uses Amorphoussilicon, which is one of the best photovoltaic materials, converts sunlight into electricity.
- 55. Classes of CrystallineSolids Crystalline substances can be described by the types of particles in them and the types of chemical bonding that take place between the particles. There are four types of crystals: ionic, metallic, covalent network, and molecular.
- 57. Ionic crystals The ioniccrystal structure consists of alternating positively- charged cations and negatively-charged anions. The ions may either be monatomic or polyatomic. Generally, ionic crystals form from a combination of Group 1 or 2 metals and Group 16 or 17 nonmetals or nonmetallic polyatomic ions. alt NaCl crystal.
- 58. Ionic crystals Ionic crystalsare hard and brittle and have high melting points. Ionic compounds do not conduct electricity as solids, but do conduct electricity when molten or in aqueous solution.
- 59. Metallic crystal -Metallic crystals consist of metal cations surrounded by a "sea" of mobile valence electrons (see figure below). These electrons, also referred to as delocalized electrons, do not belong to any one atom, but are capable of moving through the entire crystal. As a result, metals are good conductors of electricity. As seen in the table above, the melting points of metallic crystals span a wide range. Metallic crystal Metallic crystals consist of metal cations surrounded by a "sea" of mobile valence electrons (see figure below). These electrons, also referred to as delocalized electrons, do not belong to any one atom, but are capable of moving through the entire crystal. As a result, metals are good conductors of electricity. As seen in the table above, the melting points of metallic crystals span a wide range. Metallic crystal lattice with free electrons able to move among positive metal atoms.
- 60. Metallic crystal -Metallic crystals consist of metal cations surrounded by a "sea" of mobile valence electrons (see figure below). These electrons, also referred to as delocalized electrons, do not belong to any one atom, but are capable of moving through the entire crystal. As a result, metals are good conductors of electricity. As seen in the table above, the melting points of metallic crystals span a wide range. Covalent network crystals A covalent network crystal consists of atoms at the lattice points of the crystal, with each atom being covalently bonded to its nearest neighbor atoms . The covalently bonded network is three-dimensional and contains a very large number of atoms.
- 61. Metallic crystal -Metallic crystals consist of metal cations surrounded by a "sea" of mobile valence electrons (see figure below). These electrons, also referred to as delocalized electrons, do not belong to any one atom, but are capable of moving through the entire crystal. As a result, metals are good conductors of electricity. As seen in the table above, the melting points of metallic crystals span a wide range. Network solids include diamond, quartz, many metalloids, and oxides of transition metals and metalloids. Network solids are hard and brittle, with extremely high melting and boiling points. Being composed of atoms rather than ions, they do not conduct electricity in any state. Covalent Network Crystal
- 62. Metallic crystal -Metallic crystals consist of metal cations surrounded by a "sea" of mobile valence electrons (see figure below). These electrons, also referred to as delocalized electrons, do not belong to any one atom, but are capable of moving through the entire crystal. As a result, metals are good conductors of electricity. As seen in the table above, the melting points of metallic crystals span a wide range. Molecular crystals Molecular crystals typically consist of molecules at the lattice points of the crystal, held together by relatively weak intermolecular forces The intermolecular forces may be dispersion forces in the case of nonpolar crystals, or dipole-dipole forces in the case of polar crystals. Some molecular crystals, such as ice, have molecules held together by hydrogen bonds. Ice crystal structure
- 63. Metallic crystal -Metallic crystals consist of metal cations surrounded by a "sea" of mobile valence electrons (see figure below). These electrons, also referred to as delocalized electrons, do not belong to any one atom, but are capable of moving through the entire crystal. As a result, metals are good conductors of electricity. As seen in the table above, the melting points of metallic crystals span a wide range. When one of the noble gases is cooled and solidified, the lattice points are individual atoms rather than molecules. In all cases, the intermolecular forces holding the particles together are far weaker than either ionic or covalent bonds. As a result, the melting and boiling points of molecular crystals are much lower. Lacking ions or free electrons, molecular crystals are poor electrical conductors. Molecualar Crystal
- 64. Properties of CrystallineSolids Crystalline solids have a sharp melting point and start melting when it reaches a particular temperature. The shape of crystalline solids is definite and has typical arrangements of particles. They show cleavage property, i.e., when they are cut with the edge of a sharp tool, they split into two pieces, and the newly generated surfaces are smooth and plain. They have definite heat of fusion (amount of energy needed to melt a given mass of solid at its melting point). Crystalline solids are anisotropic, which means their physical properties, like electrical resistance or refractive index, show different values when they are measured along with different directions in the same crystal. Crystalline solids are true solids. Properties of the Major Classes of Solids
Editor's Notes
- #19 let's take water (H2O) as an example. In a water molecule, the oxygen atom is more electronegative than the hydrogen atoms, so it pulls the shared electrons closer to itself, creating a partial negative charge (δ-) on the oxygen atom and partial positive charges (δ+) on the hydrogen atoms. These partial positive hydrogen atoms in one water molecule are attracted to the partial negative oxygen atoms in neighboring water molecules, forming hydrogen bonds. It's like a friendly handshake between water molecules!
- #21 The most common example is salt in water. The sodium (Na+) cation attracts the partially negative oxygen (O), while the chlorine (Cl-) anion attracts the partially positive hydrogen (H).
- #60 Diamond is a network solid and consists of carbon atoms covalently bonded to one another in a repeating three-dimensional pattern. Each carbon atom makes for single covalent bonds in a tetrahedral geometry.