The Answer: Lead

Explanation:
- Conductivity of Heat: The ability of a substance to conduct heat is known as its thermal conductivity. Metals are generally good conductors of heat because they have a high thermal conductivity.
- Poor Conductors: However, some metals have a relatively low thermal conductivity and are considered to be poor conductors of heat. These metals do not allow heat to pass through them easily.
- Lead: Lead is one such metal that is a poor conductor of heat. It has a low thermal conductivity compared to other metals.
- Properties of Lead: Lead is a soft and heavy metal. It has a low melting point and a low boiling point. These properties contribute to its low thermal conductivity.
- Atomic Structure: Lead has a unique atomic structure that affects its thermal conductivity. It has a relatively large atomic radius and a high number of outer electrons. These factors result in inefficient transmission of heat energy through the metal.
- Applications: The poor conductivity of lead makes it useful in certain applications. For example, lead is used as a shield against radiation because it can absorb and block radiation effectively. Lead is also used in plumbing applications because it does not readily transfer heat, reducing the risk of burns from hot water.
- Other Options: Zinc, iron, and gold are all better conductors of heat compared to lead. Zinc and iron are commonly used in various industries due to their high thermal conductivity. Gold, although a good conductor, is not as efficient as zinc or iron. However, it is often used in electronics due to its excellent electrical conductivity and resistance to corrosion.
- Conclusion: In conclusion, lead is the metal that is a poor conductor of heat. Its unique atomic structure and properties contribute to its low thermal conductivity, making it useful in specific applications.

Because the electrons of the Gold element are not efficient to conduct heat