Aim: How Do Metal Atoms Bond in a Metal? Do Now: take out homework and compare responses

What type of bonding occurs in metal? All metal elements have metallic bonding between each atom of that metal. Q:Which substance contains particles held together by metallic bonds? A) Ni(s) B) Ne(s) C) N2(s) D) I2(s) Reason: Nickel is the only metal listed. Metal elements have metallic bonds between the metal atoms.

Metallic Bonding Metallic bonding consists of the attraction of the free-floating valence electrons from the positively charged metal ions Positive metal ions in a sea of electrons. Electrons are shared amongst every metal ion. (sea of mobile electrons)

Structure of Metals The metal ions are in a fixed position of a crystal lattice and the electrons are free to move throughout the lattice. A crystal lattice describes the periodic arrays of a solid. The bond results from the attraction between the free moving electrons and the positive ions.

Questions Which type of bonding involves positive ions immersed in a sea of mobile electrons? A) ionic B) nonpolar covalent C) polar covalent D) metallic Which factor distinguishes a metallic bond from an ionic bond or a covalent bond? A) the mobility of electrons B) the mobility of protons C) the equal sharing of electrons D) the unequal sharing of electrons Reason: The key term is sea of mobile electrons. This always refers to metallic bonds.

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Conductivity of Metals Good conductors of heat Metals conduct electricity because of the free moving electrons Electricity is energy due to the flow of electrons

Malleability of Metals Metals are malleable When a force is applies the metal kernels move to a new location, changing the shape of a metal.

Crystalline structures Metals are arranged in very compact and orderly patterns. Metal atoms crystallize in characteristic patterns.

Questions The ability to conduct electricity in the solid state is a characteristic of metallic bonding. This characteristic is best explained by the presence of A) high ionization energies B) high electronegativities C) mobile electrons D) mobile protons Reason: In an sample of metal, all the metal atoms are sharing each other’s electrons, allowing the electrons to be mobile.

Ionic Compounds are brittle. Metals are malleable High melting points and boiling points Good conductor of electricity (solid and liquid) Good conductor of electricity (in solution and when melted)

Alloys Alloys are mixtures composed of two or more elements, at least of which is a metal. Alloys are usually stronger than their individual components Steel: iron and carbon, boron, chromium, manganese, molybdenum, nickel, tungsten, vanadium.

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The ability to conduct electricity in a solid state is a characteristic of metallic bonding. This characteristic is best explained by A. high ionization energies B. high electronegativities C. mobile electrons D. mobile protons

Which element consists of positive ions immersed in a “sea” of mobile electrons? A. sulfur B. nitrogen C. calcium D. chlorine