Undergraduate
  1. General chemistry  1.1. Introduction to Chemistry  1.2. Atomic Structure  1.2.1. Subatomic particles  1.2.2. Atomic Model  1.2.3. Quantum numbers  1.2.4. Electron Configuration  1.2.5. Periodic trends  1.2.6. Isotopes and their applications  1.3. Chemical bond  1.3.1. Ionic bond  1.3.2. Covalent bonds  1.3.3. Metal Bond  1.3.4. Hybridization  1.3.5. Molecular geometry and VSEPR theory  1.3.6. Bond polarity and dipole moment  1.4. Stoichiometry  1.4.1. Mole concept  1.4.2. Empirical and molecular formula  1.4.3. Limiting reactant and excess reactant  1.4.4. Percent Yield and Purity  1.4.5. Dilution calculation  1.5. States of matter  1.5.1. Gas Laws  1.5.2. Matter and Intermolecular Forces  1.5.3. Solid and Crystal Structures  1.5.4. Phase diagram  1.5.5. Plasma and supercritical fluid  1.6. Chemical reactions  1.6.1. Types of Chemical Reactions  1.6.2. Balancing Chemical Equations  1.6.3. Thermochemical reactions  1.6.4. Reaction energy profiles  1.7. Solutions and Mixtures  1.7.1. Concentration units  1.7.2. Syndrome properties  1.7.3. Solubility and Solubility Rules  1.7.4. Henry's Law and Raoult's Law  1.7.5. Partition coefficient  1.8. Chemical equilibrium  1.8.1. Law of mass action  1.8.2. Le Chatelier's principle  1.8.3. Reaction quotient  1.8.4. To use this online calculator for Equilibrium Constant, enter Equilibrium Constant (Eq.) and hit the calculate button. Here is how the Equilibrium Constant calculation can be explained with given input values -> 0.05 = 0.05/0.  1.8.5. Acid-base balance  1.9. Acids and bases  1.9.1. Arrhenius, Brønsted–Lowry, and Lewis definitions  1.9.2. pH and pOH  1.9.3. Acid-base titration  1.9.4. Buffer Solution  1.9.5. Acid-base indicator  1.9.6. Polyprotic Acids and Bases  1.10. Electrochemistry  1.10.1. redox reactions  1.10.2. Galvanic and Electrolytic Cells  1.10.3. Nernst equation  1.10.4. Electrolysis  1.10.5. Faraday's laws of electrolysis  1.11. Thermodynamics  1.11.1. Laws of Thermodynamics  1.11.2. Enthalpy, entropy and Gibbs free energy  1.11.3. Spontaneity of reactions  1.11.4. Thermodynamic cycles (Hess's law, Carnot cycle)  1.12. Kinetics  1.12.1. Rate law and reaction order  1.12.2. Activation Energy and Catalyst  1.12.3. Collision theory  1.12.4. Reaction mechanism  1.12.5. Transition state theory
  2. Organic chemistry  2.1. Structure and relationships  2.1.1. Hybridisation in Carbon Compounds  2.1.2. Resonance and aromatization  2.1.3. Molecular orbitals  2.1.4. Inductive and mesomeric effects  2.2. Hydrocarbons  2.2.1. Hydrocarbons  2.2.2. Alkene  2.2.3. Alkynes  2.2.4. Aromatic compounds  2.2.5. Cycloalkanes and Conformation  2.3. Functional Group  2.3.1. Alcohols and phenols  2.3.2. Ethers and epoxides  2.3.3. Aldehyde and ketone  2.3.4. Carboxylic acids and derivatives  2.3.5. Amin  2.3.6. Esters and amides  2.3.7. Thiols and sulfides  2.4. Stereoscopic  2.4.1. Isomerism in Stereochemistry  2.4.2. Chirality and optical activity  2.4.3. Structural analysis  2.4.4. Diastereomers and Enantiomers  2.5.1. Substitution reactions  2.5.2. Elimination reactions  2.5.3. Addition reactions  2.5.4. Radical reactions  2.5.5. Rearrangement reactions  2.5.6. Pericyclic Reactions  2.6. Spectroscopy and structural analysis  2.6.1. Infrared Spectroscopy  2.6.2. Nuclear magnetic resonance spectroscopy  2.6.3. Mass Spectrometry  2.6.4. UV-visible spectroscopy  2.6.5. X-ray crystallography  2.7. Polymer chemistry  2.7.1. Addition and Condensation Polymers  2.7.2. Polymerization mechanism  2.7.3. Biodegradable Polymer  2.7.4. Conducting and smart polymers
  3. Inorganic chemistry  3.1. Coordination chemistry  3.1.1. Ligands and coordination compounds  3.1.2. Crystal field theory  3.1.3. Molecular Orbital Theory in Coordination Compounds  3.1.4. Jahn–Taylor distortion  3.2. Main Group Chemistry  3.2.1. Alkali and alkaline earth metals  3.2.2. Halogens and Noble Gases  3.2.3. Transition metals and their complexes  3.2.4. Lanthanides and Actinides  3.3. Solid state chemistry  3.3.1. Crystal lattices and unit cells  3.3.2. Defects in solids  3.3.3. Electrical and magnetic properties  3.3.4. Superconductivity  3.4. Bio-inorganic chemistry  3.4.1. Metal ions in biology  3.4.2. Enzymatic reactions with metals  3.4.3. Metal poisoning and detoxification  3.4.4. Metalloproteins and Metalloenzymes
  4. Physical chemistry  4.1. Quantum Chemistry  4.1.1. Wave–particle duality  4.1.2. Schrödinger Equation  4.1.3. Quantum Numbers and Orbitals  4.1.4. Atomic and molecular spectroscopy  4.2. Statistical mechanics  4.2.1. Maxwell–Boltzmann distribution  4.2.2. Partitioning functions  4.2.3. Bose–Einstein and Fermi–Dirac statistics  4.3. Chemical thermodynamics  4.3.1. Gibbs Free Energy  4.3.2. Phase transition  4.3.3. Thermodynamic efficiency  4.4. Surface chemistry  4.4.1. Absorption and Catalysis  4.4.2. Colloids and Emulsions
  5. Analytical Chemistry  5.1. Classical methods  5.1.1. Gravimetric Analysis  5.1.2. titrimeter  5.2. Instrumental methods  5.2.1. Chromatography  5.2.2. Spectroscopy  5.2.3. Electroanalytical methods  5.2.4. X-ray diffraction
  6. Industrial Chemistry  6.1. Petrochemistry  6.2. Chemical engineering principles  6.3. Green Chemistry  6.4. Pharmaceuticals and Drug Synthesis
  7. Biochemistry  7.1. Carbohydrates  7.2. Proteins and enzymes  7.3. Lipids and membranes  7.4. Nucleic acids  7.5. Metabolism and Bioenergetics  7.6. Enzyme kinetics and mechanism

Undergraduate → Inorganic chemistry → Main Group Chemistry ↓


Lanthanides and Actinides


The study of the lanthanides and actinides is an interesting and essential part of inorganic chemistry, because of their unique position in the periodic table and their important role in both scientific advancements and industrial applications. Today, we'll embark on a journey to understand these fascinating groups of elements, taking a deep look at their chemistry, properties, and applications.

Introduction to lanthanides and actinides

Lanthanides and actinides are placed at the bottom of the periodic table, often called f-block elements because their valence electrons enter the f-orbital. Despite being grouped together, they display a rich variety of chemical behaviour and properties.

Lanthanides

The lanthanides include 15 elements, ranging from lanthanum (La, Z=57) to lutetium (Lu, Z=71). They are named after the first element in the series, lanthanum. The lanthanide series is known for its lanthanide contraction, which refers to the abnormal decrease in atomic and ionic radii as one goes from left to right across a period. This is mainly due to the poor shielding effect exhibited by the 4f electrons.

Actinides

The actinides include 15 metallic elements ranging from actinium (Ac, Z=89) to lawrencium (Lr, Z=103). Unlike the lanthanides, the actinides are characterized by being able to form actinide elements with higher oxidation states and show more varied chemistry due to the 5f, 6d, and 7s orbitals being closer in energy. Many actinides are radioactive and play an important role in nuclear chemistry.

Example of Lanthanide Elements

Electronic configuration

Understanding the electronic configuration of the lanthanides and actinides is important for predicting their chemical properties. The general configuration is represented as:

Lanthanides: [Xe]4f1-14 5d 0-1 6s 2
Actinides: [Rn]5f1-14 6d 0-1 7s 2

The electronic structures show that these elements have good conductivity and high chemical reactivity, making them suitable for a variety of applications.

f-block elementsLanthanides: La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, LuActinides: Ac, Th, Pa, U, Np, Pu, Am, Cm, Bk, Cf, Es, Fm, Md, No, Lr

Physical properties

Both lanthanides and actinides are known for their unique physical properties.

Lanthanides

Lanthanides usually have a bright metallic luster and are prone to darkening in air. Except for lanthanum and lutetium, most of them have strong paramagnetic properties due to unpaired 4f electrons. Additionally, they have relatively high densities and melting points. Lanthanum is a notable exception with a relatively low melting point. Most lanthanides have similar general properties such as softness and high ductility.

Actinides

The actinides, on the other hand, are more diverse. While some, such as thorium and uranium, are dense and have high melting and boiling points, others have more complex structures that affect their state and properties. Actinides, such as plutonium, are important to nuclear reactors because of their ability to release substantial thermal energy upon radioactive decay.

Chemical properties

Lanthanides

Lanthanides generally exhibit a +3 oxidation state, which symbolizes their normal valency. While other oxidation states exist, they are less stable. Lanthanum is a prominent example of a lanthanide with a +3 oxidation state as shown below:

La → La 3+ + 3e⁻

Lanthanides are strong reducing agents, their activity being reflected in their reactivity with air, halogens, hydrogen and other non-metals. The following reaction shows the reactivity of lanthanides with water:

2Ln + 6H2O → 2Ln(OH)3 + 3H2 ↑

Actinides

Actinides exhibit more varied oxidation states which makes them versatile in chemical reactions. Uranium exhibits oxidation states ranging from +3 to +6 which makes it important for nuclear fuel processing:

UO22+ ↔ U4+ + O2

In addition, actinides readily form complexes with ligands due to their high charge-to-radius ratio, which increases their chemical reactivity. Their high electron count allows exchange interactions that result in attractive magnetic properties.

Application

The applications of the lanthanides and actinides extend across many fields, including electronics, medicine, and energy production.

Lanthanides

  • Neodymium: Used in the production of powerful magnets found in hard drives, headphones and wind turbines.
  • Europium: Integral to phosphorescent displays in television screens and LEDs.
  • Cerium: Used in catalytic converters and crude oil refining.

Actinides

  • Uranium: Fuels nuclear reactors, providing significant energy production capability and showing promise in space applications.
  • Plutonium: It is used to produce energy in power plants and is also used in the synthesis of nuclear weapons.
  • Thorium: Proposed as an alternative nuclear fuel due to its high abundance and low radioactive waste production.

Environmental and safety concerns

The handling and use of the lanthanides and actinides require special precautions, particularly because of the radioactivity of the actinides. Radioactive waste management becomes important because of the potential environmental hazards and the need to protect human health.

Regulatory frameworks govern their use and disposal to minimise ecological impact and ensure safety. Effective strategies include geological disposal for long-term isolation and advanced reactor designs that minimise waste generation.

Management and disposal of radioactive elements

Conclusion

The fascinating world of the lanthanides and actinides provides a complex but rewarding field of study in inorganic chemistry. While they share similar characteristics, their unique physical, chemical and electronic properties lead to diverse applications ranging from advanced technology development to sustainable energy production. This journey provides a foundation for future explorations into the complex behaviour of these elements as we aim for innovative applications and responsible management of valuable resources.


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