metallic-bonding

Metallicbonding1.Metallicbonding:electrostaticattractionbetweenalatticeofpositiveionsanddelocalizedelectrons.2.ThestrengthofmetallicbondingsThemoreelectronsofeachatomshareswitheachother,thestrongerthemetallicbonding.Thesmallerthemetalatoms,thestrongerthemetallicbondings.Exercise1：MetalnameMeltingpoint（K）Sodium371Magnesium923Aluminium933MetalnameMeltingpoint(K)Lithium454Sodium371Potassium3373.Propertiesofmetals(1)haveveryhighmeltingandboiling:metallicbondsareverystrongandsoalargeamountofenergyisneededtobreakthem.(2)Metalsaregoodconductorsof:heatthefreeelectronscantakeinheatenergy,whichmakesthemmovefaster.electricitythefreeelectronscancarryanelectricalcharge.malleable：canbebentandpressedintoshapeforceductile：canbedrawnoutintowires.(3)Malleable(可塑性)&ductile（延展性）thelayersofthelatticecanslideovereachotherwithoutbreakingthebonds.4.Thepropertiesofalloy（合金）Alloy:Mixtureofmetalandmetal(ormetalandnon-metals)Lessmalleableandductilethanthepuremetal:Thesizeoftheatomsinlatticechanged.It’slesseasyforlayertoslideovereachother.Homework：1.P652,32.Exercisepaper