How to Understand Magnetic Behaviour
Magnetic behaviour can be seen in a variety of substances. We have paramagnetic compounds, which are attracted to the magnetic field. Paramagnetism is the name for this phenomenon. When a substance has one or more unpaired electrons, it has a paramagnetic property. A substance becomes ferromagnetic when it gains a permanent magnetic moment, and the phenomenon is known as ferromagnetism. On the other hand, we have diamagnetic compounds, which are chemicals that are repelled by a magnetic field. When a substance includes exclusively paired electrons, it exhibits diamagnetism.
The majority of transition elements are paramagnetic. The magnetic characteristics are caused by unpaired electrons in (n-1) d orbitals. As the number of unpaired electrons grows from one to five, the paramagnetic property of transition metals increases from left to right. The maximum paramagnetic property is seen in the intermediate elements. As the number of unpaired electrons decreases, so do the magnetic characteristics. Diamagnetic behaviour is seen in transition metals with paired electrons.
Determining the metal and non-metal can be based on this fact which element has a positive and negative ion. The negative ion element comes in the series of metal and positive ions belong to the metal category. To read out the physical and chemical properties of an element, they are arranged in a periodic table in form and column format. The transition elements are those elements which do not comprise the full electronic configuration in the oxidation stage. Generally, it belongs to d-block elements.
Magnetic properties
An electron is a negatively charged particle that spins on its own axis and circulates around the nucleus. The orbital motion and spin of the electron produce a magnetic field. The flow of electric current in a closed circuit is quite similar to the spinning of an electron in an orbit. As a result, an unpaired electron is thought to be a tiny magnet with a distinct magnetic moment. When a substance having an unpaired electron is placed in a magnetic field, the unpaired electron interacts with the applied field. As a result, an attractive force is exerted, revealing the paramagnetic feature. The magnitude of the magnetic moment is determined by the number of unpaired electrons. The magnetic moment and paramagnetic behaviour of a substance increase as the number of unpaired electrons increases.
When it comes to paired electrons, each pair's electrons will have the opposite spin. In nature, the magnetic field formed by electrons of the same pair is equal and opposing. As a result, the magnetic field formed by one electron is cancelled by the magnetic field induced by the other. As a result, the magnetic moment has no net effect. These materials have diamagnetic properties and are repelled by the applied magnetic field.
The d-block element in the periodic table will show the magnetic property as their (n-1) d orbital owns the unpaired electrons. The higher the number of the unpaired electron in (n-1) element electronic configuration, they will tend to achieve the maximum magnetic behaviour. It is generally observed that the transition element ion; will exhibit paramagnetic behaviour. It can be easily attracted by the magnetic field.
Trends of The Transition Element
As the number of unpaired electrons increases from 1 to 5, the magnetic moments increase. As a result, they will reach on the verge of the increased paramagnetic and decreased diamagnetic
Some transition elements have the paired electrons in (n-1) d orbital. It does not attract a magnetic field. These paired electrons are known as the diamagnetic.
Some metals have high paramagnetic i.e. it contains permanent paramagnetic. Hence, these transition elements are termed as ferromagnetism. The best example of ferromagnetism is Co and Ni.
Magnetic Properties Of Transition Metal Complexes
Prediction of magnetic property is not easy unless there is a sure confirmation to how many unpaired electrons in the outermost cells. Electronic configuration and atom size play an important role. The magnetism of any compound has been achieved by electronic spin, the number of an unpaired electron to measure out how magnetised the compound is.
The interesting fact of this compound is to yield the magnets. Metal complexes have unpaired electrons and thus, adopt the magnetic behaviour. The spin of each electron is represented by the quantum number Ms as +1/2 and -1/2. The spin has a flat effect as the electrons are coupled to each other. In case these electrons get single, it creates a weak magnetic field. The availability of a single electron will increase the paramagnetic effect.
Transition Elements Magnetic Properties
Achievement of the magnetic property takes place as the direction of the quantum number is in the opposite direction. Let us learn the characteristics of the transition element.
These elements contain high melting and boiling points.
These elements have different valance in their outermost shell. Thereby, it has different oxidation stages.
It forms the coloured compound and chemical inorganic complex due to the existence of colour ions.
These elements have paramagnetic behaviour rather than diamagnetic behaviour.
The most common examples of the transition elements are copper, iron, and silver. This is the abundant transition element.
Magnetic Properties Of The First Transition Series
The position of the first transition series lies amid the fourth, fifth, sixth, and seventh groups. It consists of a coloured compound effect due to internal d-d transfers. The magnetic properties can conclude with theories such as Lenz’s, curie, and quantum mechanics.
Explain The Magnetic Properties of Transition Elements
Without any clue and facts, it is hard to explain whether a particular element and compound are paramagnetic or not. So, there sure is a need to make the electronic configuration and see if the configuration leads to paired and unpaired electrons. In case it holds the unpaired electrons in (n-1)d shells, then it has the paramagnetic and ferromagnetic behaviour. Take the element of transition elements e.g. Zinc (Zn) to determine if it is magnetic or not.
Steps for Determining Magnetic Properties
The electronic configuration of Zn atom is 4s2 3 d 10
Sketch of the valence orbital – Image will be uploaded soon
There is no unpaired electron.
Due to the unavailability of unpaired electrons, it does not exhibit paramagnetic behaviour.
Conclusion:
This article talks about the electrical configurations of transition elements and how they differ from that of other transition metals like, zinc, cadmium, and mercury, which are not considered transition elements. The properties of the rest of the d-block elements, on the other hand, are very similar, and this likeness can be seen down each row of the periodic table.
FAQs on Magnetic Properties of Transition Elements
1. What are the main types of magnetic properties shown by transition elements?
Transition elements primarily exhibit three types of magnetic properties based on their interaction with an external magnetic field:
- Paramagnetism: This is the most common property, where substances are weakly attracted by a magnetic field. It is caused by the presence of one or more unpaired electrons in the d-orbitals.
- Diamagnetism: This property is shown by substances that are weakly repelled by a magnetic field. It occurs when all electrons in the d-orbitals are paired, causing their magnetic moments to cancel each other out.
- Ferromagnetism: This is an extreme form of paramagnetism where certain substances, like iron (Fe), cobalt (Co), and nickel (Ni), are very strongly attracted to magnetic fields and can be permanently magnetised.
2. Why are most transition elements and their compounds paramagnetic?
Most transition elements and their compounds are paramagnetic because of the presence of unpaired electrons in their (n-1)d orbitals. Each unpaired electron, due to its orbital motion and spin, acts like a tiny magnet and possesses a magnetic moment. When placed in an external magnetic field, these individual magnetic moments align with the field, resulting in a net attraction. The more unpaired electrons an element has, the stronger its paramagnetic character.
3. How is the magnetic moment of a transition metal ion calculated?
For transition metal ions, the magnetic moment is primarily due to the spin of unpaired electrons. It is calculated using the 'spin-only' formula:
µ = √n(n+2)
Here, 'n' represents the number of unpaired electrons and 'µ' is the magnetic moment, measured in Bohr Magnetons (BM). For example, a Ti³⁺ ion (3d¹) has one unpaired electron (n=1), so its magnetic moment is √1(1+2) = √3 ≈ 1.73 BM.
4. How can you determine if a transition element ion like Fe²⁺ or Zn²⁺ is paramagnetic or diamagnetic?
To determine the magnetic property, you must first write the electronic configuration of the ion and check for unpaired electrons.
- For Fe²⁺ (Iron): The atomic number of Fe is 26. Its configuration is [Ar] 3d⁶ 4s². For the Fe²⁺ ion, two electrons are lost from the 4s orbital, giving the configuration [Ar] 3d⁶. The 3d orbital has four unpaired electrons, making Fe²⁺ strongly paramagnetic.
- For Zn²⁺ (Zinc): The atomic number of Zn is 30. Its configuration is [Ar] 3d¹⁰ 4s². For the Zn²⁺ ion, two electrons are lost from the 4s orbital, giving the configuration [Ar] 3d¹⁰. The 3d orbital is completely filled, meaning there are zero unpaired electrons. Therefore, Zn²⁺ is diamagnetic.
5. Why are Zinc (Zn), Cadmium (Cd), and Mercury (Hg) not considered typical transition metals based on their magnetic properties?
Zinc, Cadmium, and Mercury are not considered typical transition metals because they have completely filled d-orbitals (d¹⁰ configuration) in their ground state as well as in their most common oxidation state (+2). A defining characteristic of transition metals is a partially filled d-orbital. Since Zn, Cd, and Hg lack unpaired d-electrons, they do not exhibit paramagnetism and are instead diamagnetic. This differentiates them from other d-block elements that show variable oxidation states and strong paramagnetic behaviour.
6. What is the fundamental difference between paramagnetism and ferromagnetism in transition elements?
The key difference lies in the strength and permanence of the magnetic effect. Paramagnetism is a weak, temporary attraction to a magnetic field that only lasts while the field is applied. It arises from individual, unaligned unpaired electrons. In contrast, ferromagnetism is a very strong attraction where the magnetic moments of unpaired electrons in large groups of atoms (called domains) align spontaneously. This alignment persists even after the external magnetic field is removed, allowing ferromagnetic materials like iron to become permanent magnets.
7. How do the unpaired electrons responsible for magnetic properties also explain why transition metal compounds are often coloured?
The same unpaired electrons in the d-orbitals are responsible for both paramagnetism and colour. While their spin causes magnetism, their presence in a partially filled d-orbital allows for a phenomenon called d-d transition. When visible light passes through the compound, an electron absorbs energy of a specific wavelength to jump from a lower-energy d-orbital to a higher-energy d-orbital. The light that is not absorbed is transmitted, and its colour is what we perceive. Therefore, the presence of partially filled d-orbitals is the common origin for both these distinct properties.
