Author: Rimsha Nazir
Introduction
Transition metals are among the most versatile elements in the periodic table. These are found in the d-block. These metals exhibit unique properties that make them essential in industrial, biological, and technological applications. In this blog, we’ll explore the chemistry of transition metals, their characteristics, and their real-world significance.
Transition Elements
Definition
The elements having partially filled d-orbitals in their neutral atomic state or in their common ionic states. These have the ability to form stable cations with incompletely filled d-orbitals.
Example
Iron (Fe), Nickel (Ni), and Manganese (Mn) are the transition elements.
- These are the elements from group 3 to group 12.
- Total no. of transition elements = 38 elements
- These are also called Transition Metals.
- These elements are called so because they show the transitional behavior between s and p-block elements.
- These are also called d-block elements.
- Thus, according to this definition, Zn, Cd, Hg, and their divalent cations should be excluded from d-block elements since they do not have partially filled (n-1) d-orbitals. Similarly, Cu, Ag, Au, and their monovalent cations are also not considered to be transition metals or ions.
Location
Transition elements are located in the center of the periodic table flanked by the s and p-block elements in the periodic table.
General Electronic Configuration of Transition Elements
The general valance shell electronic configuration of transition elements is:
(n-1) d1…..10 ns0,1,2
Characteristics of Transition Elements
Variable Oxidation State
- These elements show variable (more than one) oxidation states, which is due to the involvement of d-electrons in bonding.
- For example, iron (Fe) shows +2 and +3 oxidation states.
- Manganese (Mn) exhibits oxidation states ranging from +2 to +7.
Formation of Colored Compounds
- Transition elements form vividly colored compounds due to d-d transitions when light is absorbed.
- The color of the ions is related to the number of unpaired electrons.
Alloy Formation
They form alloys with one another and with other metals, e.g.,
- Brass= Cu-Zn
- Bronze = Cu-Zn-Sn
- German silver = Cu-Zn-Ni.
Catalytic Properties
These are used as catalysts in various industrial and biological processes due to their variable oxidation state.
- Iron (Fe) in the Haber Process – Catalyzes ammonia production from nitrogen and hydrogen. For example,
- Platinum (Pt) in catalytic converters – Converts harmful car exhaust gases (CO, NOx) into less toxic substances.
- Vanadium (V) in sulfuric acid production – Used in the Contact Process.
Metallic Character
- All the transition elements are metals.
- They are hard, malleable, and ductile.
- These are good conductors of heat and electricity.
Melting And Boiling Points
These elements have high melting and boiling points as compared to s-block elements.
Ionization Potentials
Their ionization potential values lie in between the s and p-block elements.
It means that these are less electropositive than s-block elements but more electropositive than p-block.
Complex Formation
The cations of transition metals have a tendency to form complexes with several ligands.
Paramagnetic Behavior
Many transition metals, atoms, and cations with partially filled d-orbitals exhibit paramagnetic behavior, i.e., they are attracted to magnetic fields.
Interstitial Compounds
Transition metals have the ability to form interstitial compounds because they have large atomic size and crystal structure, which contains voids or interstices where small non-metallic elements (H, B, C, N, etc.) can fit.
For example, TiC.
Biological And Industrial Applications
Transition metals have a significant applications in biology and industrial processes.
Role in Biology
Transition metals are essential for biological processes. For example,
- Hemoglobin contains iron (Fe), which helps RBC in the transport of oxygen.
- Chlorophyll contains Magnesium (Mg), which is an essential molecule for the photosynthesis process.
Industrial Applications of Transition Metals
Transition metals have a wide range of applications in various industries.
1. Construction and Engineering
- Titanium is used in the construction of aircraft and implants.
- Steel (Fe & C) is used in buildings, bridges, and road construction.
2. Jewelry And Luxury Items
- Gold (Au) and silver (Ag) are used in making jewelry. Silver is also used in the manufacturing of mirrors.
- Platinum (Pt) is used in making fine jewelry and as a catalyst.
3. Electronics
- Copper, due to its excellent electrical conductivity, is used in wiring and motors.
Conclusion: The Power of Transition Metals
Transition metals are unsung heroes of chemistry. These are essential to nature, industry, and technology. From oxygen transport in blood to industrial catalysts, their unique properties—variable oxidation states, strong metallic bonds, and vibrant colors—make them indispensable. Found in everything from aerospace materials to electronics, these elements shape the modern world. As research advances, transition metals will continue to drive innovation and sustainability.
Read More: Quantum Chemistry and Electronic Structure Calculations
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