This chapter discusses the Group 2 elements. Known as the alkaline earth metals — beryllium, magnesium, calcium, strontium, barium, and radium — these are characterised by metallic bonding and typically form ionic compounds, though beryllium exhibits more covalent bonding. Group 2 metals are harder and denser than Group 1 metals, with reactivity and metallic radius increasing down the group. The chapter examines the extraction of these elements, highlighting magnesium and calcium as the most commercially significant. The chemical behaviour of Group 2 elements, including their reactions with water, is explored, with a focus on trends in their oxides, hydrides, halides, and nitrides. Lastly, the chapter explores the industrial uses of these metals, from construction materials to pyrotechnics, as well as the biological importance of magnesium and calcium.

This chapter on green chemistry emphasises the role of inorganic chemistry in advancing environmentally sustainable industrial processes. It is framed by the 12 principles of green chemistry, proposed by Anastas and Warner, which focus on reducing waste, increasing energy efficiency, and minimising the use of hazardous substances. The chapter outlines how industries, particularly the chemical sector, have historically been viewed as polluting but are now transitioning towards greener technologies. These changes are often driven by legislation and economic incentives rather than purely altruistic motives. The principles guide the design of safer chemicals and processes, with catalysts playing a crucial role in improving efficiency and reducing by-products. The development of biodegradable materials and the use of renewable feedstocks are also central to green chemistry. Lastly, real-time monitoring of chemical processes is encouraged to prevent pollution, while accident prevention is emphasised as critical for safer chemical practices.

This chapter examines the essential chemical properties of the Group 13 elements: boron, aluminium, gallium, indium, and thallium. Boron is unique as a non-metal, while the heavier elements are distinctly metallic, with aluminium being particularly abundant and commercially important. Moving down the group, metallic character increases and ionisation energies decrease. While the +3 oxidation state is common, the heavier elements show greater stability in the +1 state due to the inert pair effect. Gallium and indium are valued for their electronic and optical uses, and thallium, despite its toxicity, has specialised applications. Lastly, element 113, nihonium, is briefly mentioned as unstable, with little known about its chemistry due to its short half-life.

This chapter discusses the f-block elements, comprising the lanthanoids and actinoids. These elements exhibit complex atomic and bonding behaviours due to the involvement of f-orbitals. The lanthanoids, which fill the 4f orbitals, show relatively uniform chemical properties, favouring the +3 oxidation state and primarily forming ionic bonds. These elements are essential in high-tech applications such as light-emitting diodes (LEDs), medical diagnostics, and magnets. The actinoids, filling 5f orbitals, display greater chemical diversity, particularly in redox behaviour and covalent bonding, with early members like uranium and plutonium playing crucial roles in nuclear energy. Extraction of lanthanoids and actinoids is resource-intensive, with lanthanoids commonly sourced from minerals like bastnaesite and actinoids from uranium ores. While lanthanoids are relatively abundant, actinoids are more limited due to their radioactivity and environmental risks. Overall, f-block elements have a significant impact on both industrial applications and scientific research.

This chapter discusses the electronic and magnetic properties of d- and f-metal complexes. It explains how ligand field theory, introduced earlier in the book, aids in interpreting the electronic spectra of metal complexes, particularly through the energy levels and transitions observed. Electron-electron repulsions are significant, leading to more complex spectra than those predicted by simple ligand field theory. The chapter introduces Tanabe-Sugano diagrams, which quantify the ligand-field splitting parameter in d-metal complexes. It also explores the magnetic properties of d- and f-metal complexes, highlighting phenomena such as cooperative magnetism and spin-crossover. The unique electronic spectra of lanthanoids and actinoids, which display narrow, distinct absorption bands due to f-electrons, are discussed in detail. Lastly, the chapter covers charge-transfer bands, resulting from electron movement between ligands and metal ions, as well as selection rules, luminescence, and the specific magnetic behaviour of these complexes.

This chapter outlines the origins of matter, starting with the Big Bang, an event which produced fundamental particles. As the universe cooled, these particles combined to form atomic nuclei via the strong force, while the electromagnetic force bound electrons to nuclei, leading to the formation of atoms. Hydrogen and helium remain the most abundant elements in the universe, though nuclear reactions have synthesised many others. Atoms are characterised by their atomic number, representing the number of protons in the nucleus, and their mass number, which includes both protons and neutrons. The concept of isotopes, atoms with the same atomic number but different mass numbers, is exemplified using hydrogen's isotopes. Quantum theory is introduced to explain electron configurations, aiding in the understanding of atomic properties like ionisation energy and electronegativity. Lastly, the chapter categorises the subatomic particles relevant to chemistry, discussing their masses, charges, and roles in the formation of elements.

This chapter explores metallic bonding, characterised by delocalised electrons, and how it leads to space-filling structures in metals. It introduces unit cells as the building blocks of crystal structures and explains the role of close-packed arrangements, such as cubic close-packed (ccp) and hexagonal close-packed (hcp), in metallic and ionic solids. The concept of lattice enthalpy is explored to rationalise the stability of ionic compounds, with the Born-Haber cycle employed to calculate these values. It also examines the impact of different bonding types, including metallic and ionic, on thermal stability, solubility, and solid structures. Lastly, the role of energetics in determining preferred structural arrangements is addressed, along with an examination of trends in lattice enthalpy and their implications for solid-state reactivity.

This chapter introduces key concepts in coordination chemistry, beginning with the structures and types of ligands that bind to a metal centre. It covers coordination numbers, ranging from low (e.g., two or three ligands) to higher numbers (up to 12), which influence the geometry of complexes. The importance of isomerism, including geometrical and optical isomers, is highlighted for their role in the diversity of coordination compounds. Stability is discussed through the chelate effect and ligand-field theories, explaining the electronic structure and bonding in transition metal complexes. The chapter also examines the thermodynamic and kinetic stability of complexes, and their applications in areas such as catalysis and medicine. Finally, models such as those of the crystal-field and ligand-field theories are introduced to explain magnetic and spectroscopic properties, providing a foundation for understanding coordination compounds in various contexts.

This chapter addresses molecular symmetry and introduces group theory as a mathematical framework for systematically classifying molecular symmetries. Symmetry operations, such as rotations and reflections, are linked to symmetry elements like axes or planes, which define point groups. These point groups allow for the classification of molecules based on their symmetry characteristics. The chapter notes that character tables summarise the effects of symmetry operations on molecular orbitals, facilitating the interpretation of spectroscopic data. Symmetry analysis is also applied to determine molecular properties, including polarity and chirality. Molecules with improper rotation axes, such as tetrahedral structures, cannot be chiral, while certain symmetry elements forbid dipole moments. The chapter concludes with an exploration of symmetry's role in molecular vibrations, particularly in predicting whether vibrational modes will be infrared (IR) or Raman active.

This chapter examines the critical role of inorganic materials in the advancement of renewable energy technologies. These materials are essential for energy harvesting, conversion, and storage, particularly in devices such as solar cells, wind turbines, and batteries. They also enhance the efficiency of energy utilisation in applications such as electric vehicles, fuel cells, and low-energy lighting. The chapter delves into various energy materials, including pigments, coatings, phosphors, and photovoltaics, outlining their specific applications and underlying chemical properties. Significant attention is given to photovoltaic materials, notably silicon, as well as emerging alternatives like perovskite solar cells. Additionally, the chapter covers the use of magnetic materials in c generation and storage. It concludes by addressing innovations in energy materials designed to mitigate environmental challenges, particularly the urgent need to reduce dependence on fossil fuels.

This chapter highlights hydrogen's importance in fundamental chemistry and industrial applications. It forms compounds with nearly all elements and is crucial in processes such as ammonia synthesis, steel production, and as a clean energy carrier in fuel cells. While industrial hydrogen is primarily derived from fossil fuels, renewable methods like solar-powered water electrolysis are gaining prominence for producing green hydrogen. The chapter discusses hydrogen's dual role as a Lewis acid or base, its ability to donate or accept protons and hydride ions, and the synthesis of various hydrogen compounds, including binary hydrides. Lastly, the chapter addresses the challenge of hydrogen's low volumetric energy density and ongoing efforts to improve storage technologies.

This chapter begins with an introduction to Lewis structures and the octet rule, which accounts for the stability of molecules as atoms seek to achieve eight valence electrons. Resonance, presented as a solution for cases where a single Lewis structure is inadequate, stabilises molecules by averaging multiple possible configurations. The valence shell electron pair repulsion (VSEPR) model is then applied to predict molecular geometries, highlighting how lone pairs exert a greater influence on structure than bonding pairs. Valence bond theory explains molecular bonding through the overlap of atomic wavefunctions, illustrated by the hydrogen molecule, and applies to both homonuclear diatomic and polyatomic molecules. Molecular orbital theory explains bonding in terms of atomic orbitals combining to form molecular orbitals that extend across the entire molecule. The chapter concludes with a discussion of bond properties, such as bond length and strength, and introduces the concept of catalysis.

This chapter explores the chemistry of metal-carbon bonds involving d-block elements. It begins with a historical overview, noting early discoveries such as Zeise's salt and metal carbonyl complexes. Since the 1950s, the field has expanded significantly, aided by techniques like X-ray crystallography and spectroscopy. A key feature of d-metal organometallic chemistry is the 18-electron rule, which helps explain the stability of these compounds. Electron counting methods, including the neutral-ligand and donor-pair models, are employed to determine electron configurations and predict reactivity. Bonding in these compounds often involves σ and π interactions, with ligands such as CO playing a crucial role. The chapter also examines a variety of ligands, including phosphines and carbonyls, and their influence on metal-ligand bonding. Finally, it explores the structural and electronic properties of important organometallic complexes, emphasising their applications in industrial catalysis and organic synthesis.

This chapter examines the role of catalysts in accelerating chemical reactions without being consumed in the process. Catalysts are indispensable in both industrial and biological systems, making significant contributions to global economic output. A distinction is drawn between homogeneous catalysis, which involves organometallic and coordination complexes, and heterogeneous catalysis, which operates on solid surfaces, often incorporating nanoparticles. Key catalytic reactions, such as alkene metathesis, hydrogenation, hydroformylation, and Wacker oxidation, are explored to illustrate the broad applications of catalysis in chemical transformations. The chapter further highlights the economic and environmental advantages of catalytic processes, particularly in cleaner industrial applications, such as catalytic converters and fuel cells. The inherent complexity of catalytic mechanisms, involving multiple reaction steps and transient intermediates, emphasises the scope for ongoing research and innovation. Finally, the potential of hybrid catalysts and nanoparticle-based systems is discussed, with a focus on improving catalytic efficiency and sustainability.

This chapter reviews periodic trends, highlighting both general patterns and notable exceptions. It discusses the prevalence of radical species in elements with partially filled p, d, and f orbitals, where unpaired electrons are more common. The anomalous behaviour of first-row elements, like lithium and beryllium, is linked to their smaller size and higher electronegativities. Diagonal relationships, such as between lithium and magnesium, and the alternation effect, caused by poor screening by d orbitals, are also explored. The chapter concludes with discussions on the lanthanoid contraction's impact on d-block elements and the relativistic effects influencing the properties of heavier elements, such as gold and lead.

This chapter examines redox reactions, focusing on electron transfer processes. Oxidation involves electron loss, while reduction is electron gain, with these processes typically occurring simultaneously in redox reactions. The chapter explores the thermodynamic factors governing these reactions, using standard potentials to predict spontaneity and stability. Electrochemical methods for measuring reduction potentials are discussed, alongside how these potentials affect the stability, solubility, and reactivity of inorganic species in aqueous environments. Diagrams, such as the Latimer and Frost diagrams, are introduced to visually represent oxidation state trends and stability fields. The chapter also covers industrial and environmental applications, including metal extraction from ores and electrocatalysis.

This chapter examines the reactions of metal complexes, focusing on ligand substitution, redox reactions, and photochemical processes. Ligand substitution reactions are discussed, with rates influenced by coordination geometry, the metal centre, and ligand properties, and mechanisms classified as associative, dissociative, or interchange. The impact of ligand field stabilisation energy (LFSE), spectator ligands, and steric effects on reaction pathways in octahedral and square-planar complexes is also explored. Redox reactions are divided into inner-sphere and outer-sphere mechanisms, based on electron transfer processes and complex connectivity. The chapter concludes with an overview of photochemical reactions, electronic transitions, and experimental methods for studying reaction mechanisms, highlighting the role of kinetics.