Which among the following metal is highest electrical conductivity as well as highest thermal conductivity?

The metal with the highest electrical conductivity as well as the highest thermal conductivity is Silver (Ag). Here are the steps to answer this question:

1. Identify the properties mentioned in the question: The question asks for a metal with the highest electrical conductivity and the highest thermal conductivity.

2. Understand the properties: Electrical conductivity refers to a material's ability to conduct an electric current. Thermal conductivity refers to the property of a material to conduct heat.

3. Research or recall the metals with these properties: Different metals have different levels of electrical and thermal conductivity. Some metals like copper, gold, and silver are known for their high conductivities.

4. Compare the metals: Among these metals, silver has the highest electrical conductivity. It also has the highest thermal conductivity.

5. Answer the question: Therefore, the metal with the highest electrical conductivity as well as the highest thermal conductivity is Silver (Ag).