At what temperature does gold evaporate?
Based on the provided reference, the ideal evaporation temperature for gold is around 1,400°C.
Gold, like other substances, can transition from a solid or liquid phase directly into a gas phase. This process, often referred to in the context of thin-film deposition or high-temperature applications, depends heavily on temperature and pressure. Evaporation or sublimation (solid to gas) technically occurs at temperatures below the boiling point, with the rate increasing significantly as temperature rises. The boiling point is the temperature at which the vapor pressure of the substance equals the ambient pressure.
The reference provides specific data points regarding gold's properties related to these phase transitions.
Key Properties and Evaporation Temperature
Gold is a precious metal known for its beauty, lustrous yellow sheen, and inertness. Its physical properties dictate how it behaves under heating.
According to the reference:
- Melting Point: Gold melts at 1,064°C.
- Vapor Pressure: Gold has a vapor pressure of $10^{-4}$ Torr at 1,132°C.
- Ideal Evaporation Temperature: The ideal temperature for gold evaporation is stated as being around 1,400°C.
This indicates that while gold is molten well below 1,400°C, and exhibits a measurable vapor pressure at temperatures only slightly above its melting point (like 1,132°C), a temperature around 1,400°C is considered optimal for practical evaporation processes, likely due to achieving a sufficient vapor pressure and evaporation rate.
Here's a summary of the relevant properties from the reference:
| Property | Value | Notes |
|---|---|---|
| Melting Point | 1,064°C | Temperature where gold turns liquid. |
| Vapor Pressure (at 1132°C) | $10^{-4}$ Torr | Indication of evaporation tendency. |
| Ideal Evaporation Temp. | ~1,400°C | Temperature for optimal evaporation. |
Factors Influencing Evaporation Rate:
The rate at which gold evaporates is influenced by several factors:
- Temperature: Higher temperatures lead to higher vapor pressure and faster evaporation.
- Surface Area: A larger surface area exposed to the vacuum or atmosphere will evaporate faster.
- Ambient Pressure: Evaporation is typically done in a vacuum or low-pressure environment to facilitate the escape of vaporized atoms.
- Time: The longer gold is held at a high temperature, the more will evaporate.
While gold will evaporate at temperatures above its melting point (1,064°C), the rate becomes significant and practical for applications like thin-film deposition at temperatures closer to the stated 1,400°C.
