Question

Which of the following is diamagnetic?
A.Platinum
B.Gold
C.Tungsten
D.Niobium

Answer 1

Hint: To get the solution for this question, first understand the definition of diamagnetism and then how to check if an item is diamagnetic or not. Once this concept is understood then, it becomes easy to differentiate which item is diamagnetic, paramagnetic or ferromagnetic. Each type of magnetism has its own unique functionality which helps to identify the elements.

Complete answer:
Diamagnetic materials are weakly repelled by an external magnetic field, an applied magnetic field creates an induced magnetic field in them in the opposite direction, causing a repulsive force. Diamagnetism is a quantum mechanical effect that occurs in all materials, when it is the only contribution to magnetism, the material is called diamagnetic. Molecules or Atoms are said to be diamagnetic when they do not have any unpaired electron in their orbital.
When the electronic configuration of platinum, gold, tungsten, and niobium is checked, then it is seen that platinum has no unpaired electron, gold has one unpaired electron, tungsten has 4 unpaired electrons and niobium has 5 unpaired electrons.
Since, Platinum has no unpaired electrons in its orbital, so the molecules are weakly repelled by an external magnetic field.

Therefore, the correct answer is Option (A).

Note:
This is a pure concept-based question and if the concept is not understood properly, then it becomes tough to answer this question. Magnetism is a very interesting topic if understood properly and can also help to gain marks in exams. Understand how the magnetic field and force acts on the diamagnetic materials, then it will be easy to understand which material is diamagnetic.