Question

Substances have zero resistivity or infinite conductivity known as ________.

Hint:

When working with surds (roots), treat the radical like a variable. For example, \(2\sqrt{2} - \sqrt{2}\) is just like \(2x - x\).

Answer 1

Concept:
Electrical resistivity measures how strongly a material opposes the flow of electric current. Some materials exhibit special behavior at very low temperatures.
Explanation:

Certain materials, when cooled below a critical temperature, lose all electrical resistance.
Their resistivity becomes zero and conductivity becomes infinite.
This phenomenon is called superconductivity.
Definition:
Materials that exhibit zero resistivity and infinite conductivity are called
superconductors
.
Examples:

Mercury (below 4.2 K)
Lead
Niobium alloys \[ \boxed{\text{Answer: Superconductors}} \]