Understanding the properties of metals like malleability and ductility is fundamental in chemistry and materials science. The question asks us to identify which among the given metals possesses both of these key properties.

Understanding Malleability and Ductility in Metals

Let's define the terms:

• Malleability: This is the property of a metal that allows it to be hammered or pressed into thin sheets without breaking or cracking. Think of aluminium foil or gold leaf.
• Ductility: This is the property of a metal that allows it to be drawn into thin wires without losing its strength or breaking. Think of copper wires used in electrical circuits.

Most metals exhibit both malleability and ductility to varying degrees because of their metallic bonding structure, which allows layers of atoms to slide past each other without fracturing the material.

Analyzing the Given Metals

Let's examine each option provided:

1. Na (Sodium): Sodium is an alkali metal. It is very soft and can be cut with a knife. However, it is also highly reactive, especially with air and water. While it exhibits some metallic properties, its malleability and ductility are not as pronounced or practically useful as some other metals due to its reactivity and softness.
2. Au (Gold): Gold is a transition metal. It is famously known for being one of the most malleable and ductile metals. A single gram of gold can be hammered into a sheet covering several square meters (gold leaf) or drawn into a wire kilometers long. These properties are why gold is widely used in jewelry, coinage, and even in electronics.
3. Ce (Cerium): Cerium is a rare earth metal (specifically, a lanthanide). It is a reactive metal, tarnishing in air. While it is metallic and can be worked, its malleability and ductility are generally less emphasized or utilized compared to common transition metals like gold or copper.
4. Hg (Mercury): Mercury is unique among metals because it is a liquid at room temperature. Malleability and ductility are properties that describe how a *solid* material behaves under mechanical stress (like hammering or drawing). Since mercury is liquid, it does not exhibit malleability or ductility in the solid-state sense at standard room temperature and pressure.

Comparison of Properties

Here's a brief comparison based on typical understanding of these properties:

Based on the analysis, Gold (Au) is the metal among the options that is most well-known and significantly exhibits both high malleability and high ductility.

Conclusion

The metal from the given options that possesses both malleability and ductility properties to a significant degree, making it a classic example of these metallic characteristics, is Gold (Au).

Revision Table: Metal Properties

Additional Information: Why Metals are Malleable and Ductile

The reason metals exhibit malleability and ductility lies in their unique bonding structure, known as metallic bonding. In metallic bonding, the valence electrons are delocalized and form a 'sea' of electrons that surrounds a lattice of positive metal ions. When a force is applied to a metal, causing layers of ions to slide past each other, the delocalized electron sea acts like a glue, maintaining the attractive forces between the ions even as their positions change. This prevents the layers from repelling each other and the material from breaking, allowing it to be deformed into shapes (malleability) or stretched into wires (ductility).

Different metals have varying degrees of malleability and ductility depending on factors like the strength of their metallic bonds, atomic size, and crystal structure.