Worksheet: Metallic Bonding

In this worksheet, we will practice describing metallic bonding in terms of electrostatic attraction between nuclei and a sea of delocalized electrons.

Q1:

Which of the following is the best description of delocalized electrons in metallic bonding?

  • ACore electrons bound to metal ions
  • BCore and valence electrons that can move freely between metal ions
  • CValence electrons that can move freely between metal ions
  • DValence electrons bound to metal ions
  • ECore electrons that can move freely between metal ions

Q2:

In a sample of calcium metal, how many electrons does an atom of calcium contribute to the sea of delocalized electrons?

Q3:

In a sample of potassium metal, how many electrons does an atom of potassium contribute to the sea of delocalized electrons?

Q4:

Metals are typically shiny and electrically conductive, while ionic solids are dull and electrically insulating. Which feature of metals is responsible for this difference?

  • AThe delocalized electrons
  • BThe number of neutrons in the nuclei
  • CThe charges of the positive ions
  • DThe atomic mass of the nuclei
  • EThe crystal lattice of positive ions

Q5:

In metallic bonding, what is the dominant form of attraction between the lattice of positive ions and sea of delocalized electrons?

  • AGravitational
  • BNuclear
  • CMagnetic
  • DElectrostatic
  • ECovalent

Q6:

Shown in the diagram are the electronic structures of lithium and calcium atoms.

The melting temperature of lithium is 181C, while that of calcium is 842C. Based on the electronic structures of the atoms and the strength of their metallic bonds, explain this difference in melting temperature.

L i C a
  • AMetallic bonds are stronger in lithium as the valence electrons are closer to the nucleus, so more thermal energy is needed to break up the metal lattice.
  • BMetallic bonds are stronger in lithium as there are fewer valence electrons, so more thermal energy is needed to break up the metal lattice.
  • CMetallic bonds are weaker in lithium as there are fewer valence electrons, so less thermal energy is needed to break up the metal lattice.
  • DMetallic bonds are stronger in lithium as there are more valence electrons, so more thermal energy is needed to break up the metal lattice.
  • EMetallic bonds are weaker in lithium as the valence electrons are closer to the nucleus, so less thermal energy is needed to break up the metal lattice.

Q7:

Which of the following atoms would form a solid metal with the highest melting point?

  • A
  • B
  • C
  • D
  • E

Q8:

Which of the following atoms would form a solid metal with the highest electrical conductivity?

  • A
  • B
  • C
  • D
  • E

Q9:

Which of the following atoms would form a solid metal with the lowest thermal conductivity?

  • A
  • B
  • C
  • D
  • E

Q10:

Which of the following is the best description of electrical conduction in a solid metal?

  • APositive ions flow through a lattice of negative ions.
  • BNegatively charged elementary particles flow through a lattice of positive ions.
  • CPositively charged elementary particles flow through a lattice of positive ions.
  • DPositively charged elementary particles flow through a lattice of negative ions.
  • ENegative ions flow through a lattice of positive ions.

Q11:

Both magnesium and aluminum are good thermal conductors. However, the thermal conductivity of magnesium is lower than that of aluminum.

Why are magnesium and aluminum good thermal conductors?

  • AThermal energy is conducted via the free movement of delocalized ions.
  • BThermal energy is conducted via the vibrations of metal ions.
  • CThermal energy is conducted via the ionization of metal atoms.
  • DThermal energy is conducted via the free movement of delocalized electrons.
  • EThermal energy is conducted via the vibrations of delocalized electrons.

Why does magnesium have a lower thermal conductivity than pure aluminum?

  • AMagnesium atoms are heavier.
  • BMagnesium atoms contain fewer valence electrons.
  • CMagnesium atoms are smaller.
  • DMagnesium atoms are larger.
  • EMagnesium atoms contain more valence electrons.

Q12:

Shown in the diagram are the electronic structures of sodium and potassium atoms.

The melting temperature of sodium is 97.8C, while that of potassium is 63.5C. Based on the electronic structures of the atoms and the strength of their metallic bonds, explain this difference in melting temperature.

N a K
  • AMetallic bonds are weaker in sodium as there are fewer valence electrons, so less thermal energy is needed to break up the metal lattice.
  • BMetallic bonds are stronger in sodium as there are more valence electrons, so more thermal energy is needed to break up the metal lattice.
  • CMetallic bonds are stronger in sodium as the valence electrons are closer to the nucleus, so more thermal energy is needed to break up the metal lattice.
  • DMetallic bonds are weaker in sodium as the valence electrons are closer to the nucleus, so less thermal energy is needed to break up the metal lattice.
  • EMetallic bonds are stronger in sodium as there are fewer valence electrons, so more thermal energy is needed to break up the metal lattice.

Q13:

Which of the following has the smallest effect on the strength of a metallic bond?

  • AThe number of electrons in the metal atoms
  • BThe number of neutrons in the metal atoms
  • CThe number of protons in the metal atoms
  • DThe arrangement of the metal atoms
  • EThe radii of the metal atoms

Q14:

The atoms in a metal can alter their positions when a force is applied, as shown in the diagram.