Question

Which of the following metals is the best conductor of electricity?
(a) Nickel
(b) Gold
(c) Sodium
(d) Silver

Answer 1

Hint:The answer to this question is the element which has an atomic number equal to $47$.It is a rare element and therefore expensive.

Complete step by step answer:
Let us first try and understand what a good conductor of electricity really possesses which differentiates it from other substances which are not-so-good conductors of electricity.
-Electricity is the phenomenon of flow of current through a body or medium. Current is the flow of charges across a potential difference. Charges are nothing but species that either lack electrons or have an excess of it. The former is referred to as a positive charge whereas the latter is called a negative charge. In actuality there is nothing called a positive charge, because the only entity that is shareable between atoms are electrons and they have a negative charge. So, less electrons than normal is conventionally called positive charge.
-The wires that we use in our homes are good conductors of electricity because the materials used to build them have free electrons which behave as the charge carriers. The solution of sodium chloride in water is a good conductor of electricity because of the ions that act as the charge carriers. The ions are entities that derive themselves from neutral elements either by gaining or donating electrons. This completely depends on their individual tendencies.
-In case of metals, the bonds which bind them into a solid are called metallic bonds. These are different from covalent or electrostatic bonds. The atomic structure of these bonds show that inside a metal, the atoms have two parts: the positively charged kernel and the negatively charged valence electrons. These valence electrons are like a cloud which are spread throughout the metal. Their movement conducts electricity.
-Keeping the above factors in mind, it has been experimentally determined that the best conductor of electricity out of all the other elements in the periodic table is Silver ($Ag$).

The answer is therefore option (d).

Note:
Even if silver is the best conductor of electricity, it is still not used on a wide scale for some obvious reasons. It is because it is a rare earth metal and therefore expensive. Silver is still used in rockets and supercomputers and other hi-tech machines throughout the world where something being expensive is not a big issue. In our home appliances, copper is the most used material as a conductor of electricity.