Chemistry - Metallic Bonding

Which of these best describes why copper is considered to be a more useful metal than gold? Check all that apply. ---Copper conducts electricity more readily than gold. ---Copper reacts quickly with air and water to form a tarnish, and it corrodes more easily than gold. ---Copper conducts heat very well; therefore, it is useful in cooking equipment. ---Copper is more common on Earth than gold. ---Gold is much softer and easier to scratch, bend, or dent than copper.

-Copper conducts electricity more readily than gold. -Copper conducts heat very well; therefore, it is useful in cooking equipment. -Copper is more common on Earth than gold. -Gold is much softer and easier to scratch, bend, or dent than copper.

Check all the boxes that describe the electron sea model. --It is the simplest metal bonding model. --It is the most complicated metal bonding model. --Metallic bonding results from the transfer of valence electrons. --Metallic bonding results from the sharing of valence electrons. --The electrons are delocalized. --The electrons are attracted to specific nuclei. --The delocalized electrons serve as the glue that keeps the metal atoms together. --The electrons that are attracted to specific nuclei serve as the glue that keeps the metal atoms together.

-It is the simplest metal bonding model. -Metallic bonding results from the sharing of valence electrons. -The electrons are delocalized. -The delocalized electrons serve as the glue that keeps the metal atoms together.

Which is a characteristic of the electron sea model for metallic bonding? --Molecular orbitals overlap to produce bands. --Atomic nuclei are arranged in a regular pattern. --Electrons are in localized positions in the orbitals. --Atomic nuclei are arranged in an irregular pattern.

Atomic nuclei are arranged in a regular pattern.

Which statement best describes the basis of the band theory of metallic bonding? --Molecular orbitals overlap to form atomic orbitals in which the valence electrons of the atoms travel. --Molecular orbitals overlap to form atomic orbitals in which all electrons of the atoms travel. --Atomic orbitals overlap to form molecular orbitals in which the valence electrons of the atoms travel. --Atomic orbitals overlap to form molecular orbitals in which all electrons of the atoms travel.

Atomic orbitals overlap to form molecular orbitals in which the valence electrons of the atoms travel.

Molecular Orbitals

Atomic orbitals that combine to form shared orbitals

Which is the best metal to use in an alloy to increase its electrical conductivity? --Al --Cu --Fe --Sb

Cu

Alloy

Homogeneous mixture of two or more metals

Copper (Cu) is often used for electrical wiring and cooking pans. However, iron (Fe) is much more common on Earth than copper. Why might copper be used instead of iron, if iron is easier to obtain? A link to the periodic table has been provided for your use.

Include -Fe has fewer valence electrons than Cu. -Fe has a lower conductivity than Cu. -The lower conductivity of Fe makes it less useful for wiring and cookware. -Fe is less malleable and ductile than Cu. -The lower malleability and ductility of Fe make it less easy to form into wires or sheets.

How is the electron sea model of metallic bonding different from the band theory? How are they the same? Give at least one similarity and one difference between the models

Include: -Electron sea model: Electrons all have approximately the same energy. -Band theory: Electrons move among orbitals of different energies. -Both models: Electrons move freely among atoms (delocalized).

Delocalized electrons

Mobile electrons that are not associated with specific atoms in metal crystals

Electron sea model

Most commonly used model for binding in metals; electrons are assumed to flow easily between metal nuclei

Which property does a metal with a large number of free-flowing electrons most likely have? --very hard --very brittle --poor conductivity --good conductivity

good conductivity

Which property is better explained by the band theory than by the sea of electrons model? --ductility --thermal conductivity --luster --electrical conductivity

luster

What properties of metals are explained by its mobile electrons?

malleability ductility heat conduction current conduction luster

Which combination of factors is most suitable for increasing the electrical conductivity of metals? --more valence electrons and larger atomic radius --fewer valence electrons and larger atomic radius --more valence electrons and smaller atomic radius --fewer valence electrons and smaller atomic radius

more valence electrons and larger atomic radius

Which of the following metal atoms would have the highest conductivity? --the atom with the smallest radius and the fewest valence electrons --the atom with the smallest radius and the most valence electrons --the atom with the largest radius and the fewest valence electrons --the atom with the largest radius and the most valence electrons

the atom with the largest radius and the most valence electrons

Which is most likely the result of millions of metal atoms crowding together so that molecular orbitals become combined? --the loss of metallic properties --the formation of bands in a crystal --the loss of valence electrons to other atoms --the formation of localized valence electrons

the formation of bands in a crystal

In a piece of metal, what holds the atoms together? --the positive charges of the nuclei and the localized electrons around them --the negative charges of the nuclei and the localized electrons around them --the positive charges of the nuclei and the negative charges of delocalized electrons --the negative charges of the nuclei and the positive charges of delocalized electrons

the positive charges of the nuclei and the negative charges of delocalized electrons