At room temperature, what is the physical state of Gold (Au); solid, liquid, or gas?
The correct answer and explanation is:
Correct Answer: Solid
At room temperature, gold (Au) is in the solid state. Room temperature is generally considered to be around 20–25°C (68–77°F). At this temperature, gold maintains a fixed shape and volume, which are characteristics of solids.
Gold has a melting point of 1,064°C (1,947°F). This means it needs to be heated to over a thousand degrees Celsius before it can transition from a solid to a liquid. Since room temperature is far below this threshold, gold remains in the solid phase under normal environmental conditions.
Gold is a metal and exhibits properties typical of metallic solids: it is malleable, ductile, dense, and has a shiny luster. These properties are due to the strong metallic bonding between atoms, where electrons are delocalized and shared freely throughout the structure. This creates a stable lattice that holds the atoms together firmly, making it difficult for the material to change shape or form unless extreme heat is applied.
In terms of its atomic structure, each gold atom is tightly packed in a face-centered cubic (FCC) arrangement, a crystal structure that contributes to its strength and high density. Gold’s solid state also makes it ideal for use in jewelry, electronics, and as a monetary standard, where durability and conductivity are important.
In contrast, liquids flow and take the shape of their container, while gases spread out freely to fill available space. Gold would only be in a liquid state above its melting point and in a gas state above its boiling point, which is approximately 2,856°C (5,173°F)—conditions not commonly encountered outside of industrial settings.
Therefore, under normal conditions, gold is a solid.