Question 1: Define delocalized electrons in the context of metallic bonding.

Answer: Electrons that are not bound to any specific atom and move freely throughout the metal lattice.

Question 2: Explain how delocalized electrons contribute to the high electrical conductivity of metals.

Answer: Delocalized electrons can move freely through the metal lattice, allowing electric charge to flow easily.

Question 3: What is the primary role of delocalized electrons in metals' malleability?

Answer: They allow metal ions to slide past each other without breaking the metallic bond, enabling shaping.

Question 1: Calculate the number of delocalized electrons contributed per atom in a metallic element where each atom contributes 3 electrons to the sea of electrons. Express your answer in electrons per atom.

Answer: 3

Question 2: If a block of aluminium contains 2 x 10^23 atoms, how many delocalized electrons are present in total? (Use Avogadro's number 6.022 x 10^23 mol^-1, and aluminium molar mass 26.98 g/mol).

Answer: Approximately 2.23 x 10^23 electrons

Question 1: Describe a simple experiment to demonstrate the high electrical conductivity of metals due to delocalized electrons.

Answer: Connecting a metal wire to a battery and a light bulb; the metal conducts electricity, lighting the bulb.

Question 2: Identify two variables that could affect the outcome of the experiment demonstrating electrical conductivity in metals, and suggest safety precautions.

Answer: Variables: Thickness of wire, temperature; Precautions: Avoid short circuits, handle wires safely, ensure proper insulation.

Question 1: A sample of a metal is tested for its electrical conductivity. The resistivity measured is 2 x 10^-8 Ω·m. Explain how this value relates to the presence of delocalized electrons.

Answer: Low resistivity indicates many free electrons that facilitate easy flow of electric current, confirming delocalized electrons.

Question 1: Explain why aluminium is used in electrical wiring instead of copper, considering delocalized electrons and other factors.

Answer: Aluminium is lighter and less expensive than copper; although it has slightly fewer delocalized electrons, its good conductivity and weight advantages make it suitable for wiring, especially in high-voltage applications.

Question 2: Multiple Choice: Which property of metals is most directly explained by the presence of delocalized electrons?

Answer: Electrical conductivity