1、Gas, Liquid and Solid,high temperatures,low temperatures,Kinetic Energy,Attractive Intermolecular Forces,氣體，液體和固體,dis:d 混亂,p:tikl 微粒,kmpres 壓縮,klst 聚集,krstlan 結(jié)晶,Ionic Forces,Ion-Ion,e.g. NaCl(s),Ion-Dipole,Ions form strong forces with molecule water.,Ion-ion forces are very strong and produce high

2、boiling points and melting points.,e.g. NaCl dissolved in water,離子間作用力,離子-離子,離子-偶極分子,an,daipul,intermolecular,int(:)mlekjul,polar,pul,(Three important intermolecular interactions), Forces (non-polar molecules) Forces (polar molecules) Forces (molecules with F-H, O-H, N-H bonds).,ntrkn相互作用,disp:n,dai

3、pul偶極,haidrdn,bndi,分散力,氫鍵,Intermolecular Interactions,Dispersion,Dipole-Dipole,Hydrogen,Bonding,Dispersion Forces,The on one atom are attracted to the on a neighbouring atom. This creates an “ ” (i.e. （=id est） temporary) dipole on the first atom. The instantaneous dipole on the first atom then indu

4、ces an instantaneous dipole on the second atom. The two induced dipoles attract each other.,hi:li:m 氦,vn d: w:lz 范德華力,ilektrn 電子,nju:klis 核,nstnteinjs瞬時(shí),(van der Waals Forces),electrons,nucleus,instantaneous,Dispersion Forces (van der Waals Forces),Dispersion Forces are to a molecules The polarizabi

5、lity, the ease with which the e- cloud can be , is approximately proportional to the number of electrons and weight.,pulraizbilti極化率，極化度,prp:nl成比例的,df:m使變形,mlekjl分子的,proportional,polarizability,deformed,molecular,For example, the consist of , non-polar atoms,As the molecule (atom) increases in size,

6、 the boiling point increases, so does the polarizability, therefore dispersion forces increase. Dispersion Forces also depend upon the molecular shape.,惰性氣體,sfrkl 球形的,Neon,Argon :n,Krypton kriptn,Xeon zenn,spherical,noble gases,ni:n,Dipole-Dipole Forces,In liquids of polar molecules, oppositely ends

7、 of the molecules tend to attract each other, causing partial .,For molecules of roughly equal MWs (i.e. with similar Dispersion Forces), the molecule with the higher will have a higher boiling point due to greater Dipole-Dipole forces.,t:dd 帶電荷,lanmnt排成直線,偶極距,charged,alignment,dipole moment,Hydroge

8、n Bonding,Hydrogen bond is a special intermolecular interaction between the H atom in a polar N-H, O-H or F-H bond and an O, N or F atom.,ilektrunetiv帶負(fù)電荷,kuveilnt 共價(jià)鍵,electronegative,Properties of Liquids,Viscosity,Viscosity is the resistance of a liquid to flowing. High viscosity liquids (e.g. ,)

9、flow slowly. Low viscosity liquids (e.g. water, ) flow quickly. When a liquid flows down a tube, the molecules slide over one another. The higher the forces of attraction, the less of a tendency the liquid will have to flow, and the higher will be the viscosity.,黏度,mlsz 糖漿,機(jī)油,汽油,molasses,motor oil,g

10、asoline,Surface Tension,A molecule in the liquid is stabilized by the attraction of the other liquid molecules. A molecule on the surface will be at a higher energy than one in the bulk of the liquid. Surface tension is a measure of the strength of intermolecular attractions which pull on molecules

11、at the surface of a liquid.,blk 大量,表面張力,bulk,Surface Tension,The stronger intermolecular forces, the higher surface tension. Surface tension is responsible for the rise of a liquid such as H2O in a thin glass . This also gives rise to a when water or an aqueous solution is in a or a,is an attraction

12、 between unlike molecules,is the attraction between like- molecules,kpleri: 毛細(xì)管,minisks 新月面,pipet 吸液管,bjuret 滴管,dhi:n 粘附力,khi:n 內(nèi)聚力,capillary,meniscus,pipette,burette,Adhesion,Cohesion,Surface Tension,It is because of its high surface tension that water tends to “ ”up on a surface. Thats because a g

13、ives the minimum ratio of surface area to volume. The high surface tension of water also causes molecules on the surface to pack very closely together. This is why some insects can “walk on water”.,bi:d形成小水珠,wksi 光滑的,sfi 球體,表面積對(duì)體積的比例最小,bead,waxy,sphere,Structure of Solids,A crystalline solid possess

14、es rigid and long-range order . In a crystalline solid, atoms, molecules or ions occupy specific ( ) positions An solid does not possess a well-defined arrangement and long-range molecular order. Irregular (disordered) arrangement of atoms (or molecules) are found in an amorphous solid.,Crystalline

15、solid, e.g. Quartz (SiO2),Amorphous solid e.g. Silica Glass (SiO2),長(zhǎng)程有序,m:fs 無定形的,固定的,predictable,amorphous,Thank you!,The Crystalline Lattice,Lattice is the three dimensional array of points repeating periodically. Lattice point can be atoms, molecules and ions. Unit cell is the basic repeating str

16、uctural unit of a crystalline solid.,晶格點(diǎn),晶胞,單元,Unit cell,The unit cells stacked in 3-D space describe the bulk arrangement of atoms of the crystal. The unit cell is given by its lattice parameters：the length of the cell edges & the angles between them. while the positions of the atoms inside a unit

17、cell are described by the set of atomic positions measured from a lattice point.,原子集合體,從晶格的一個(gè)角度,Types of Solids,There are four classifications of solids, depending on the type of bonds that are present: Ionic Solids, Metallic Solids, Molecular Solids and Covalent Network Solids.,Ionic Solids,Lattice

18、 points occupied by and held together by attraction. Hard, , high melting point, poor conductor of heat and electricity Examples: All typical salts, e.g. NaCl, Ca(NO3)2, MgBr2,CsCl,ZnS,CaF2,ktain 陽離子,nain陰離子,ilektrusttik靜電的,britl 易碎的,cations,anions,electrostatic,brittle,Metallic Solids,Lattice point

19、s occupied by metal atoms held together by metallic bond Soft to very hard, low to very high melting point, excellent thermal and electrical conductivity, and,Bonding due to valence electrons (shown in blue),Strength of bonding varies between different metals, resulting in wide range of physical pro

20、perties,從軟到硬,dktal 韌性,Examples: All metals, e.g. Cu, Fe, Sn, Au, Ag,mli:bl有延展性的,di:luklaiz離域,價(jià)電子,malleable,ductile,delocalized,Molecular Solids,Lattice points occupied by molecules held by intermolecular forces Fairly soft, moderately low melting point (usually 200oC), poor thermal and electrical conductivity Examples: Argon , CH4, CO2, H2O,Covalent Network Solids,Lattice points occupied by atoms connected in network of bonds Hard, high melting point, poor conductor of heat and electricity Examples: Diamond