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Coordination compounds consist of a central metal atom or ion surrounded by ligands. Key terms include ligand (molecules/ions donating electron pairs), coordination number (number of ligand attachments to the metal), and coordination sphere (metal-ligand complex). Ligands can be monodentate (one donor atom), bidentate (two donor atoms), or polydentate (multiple donor atoms). The chelate effect stabilizes complexes with polydentate ligands. Oxidation state refers to the metal’s charge. Geometri...

Werner’s theory of coordination compounds, proposed by Alfred Werner in 1893, explains the bonding and structure of complex compounds. It states that metal atoms exhibit two types of valency: primary (oxidation state) and secondary (coordination number). The primary valency is ionizable, while the secondary valency determines the number of ligands attached to the metal. Ligands form coordinate bonds with the central metal ion, creating geometrically distinct structures like octahedral, tetrahe...

Coordination compounds consist of a central metal atom/ion bonded to surrounding ligands through coordinate covalent bonds. They follow Werner’s coordination theory, where the coordination number defines the number of ligand attachments. Ligands can be neutral molecules (H₂O, NH₃) or anions (Cl⁻, CN⁻), classified as monodentate, bidentate, or polydentate based on binding sites. These compounds exhibit unique colors, magnetism, and reactivity, widely used in medicine (cisplatin for canc...

Actinium and actinoids (elements 89–103) belong to the f-block and exhibit unique properties. Actinium (Ac) is a silvery, radioactive metal with a +3 oxidation state, used in radiation therapy. Actinoids have variable oxidation states (commonly +3, but also +4 to +7), making them chemically versatile. They are highly electropositive, reactive with halogens and acids, and mostly radioactive. Elements like uranium and plutonium are crucial for nuclear energy and weaponry, while others like thori...

Electronic configuration describes the distribution of electrons in an atom's orbitals, following the Aufbau principle, Pauli exclusion principle, and Hund’s rule. Electrons fill orbitals in increasing energy order: 1s → 2s → 2p → 3s → 3p → 4s → 3d → 4p, and so on. s-, p-, d-, and f-block elements have unique configurations affecting their chemical properties. Transition metals show irregularities due to d-orbital stability, while lanthanoids and actinoids involve f-orbitals. Pr...

Oxidation states represent the charge an atom would have if electrons were completely transferred in a bond. They help explain redox reactions, bonding, and element behavior. Elements can have multiple oxidation states due to electron configurations and bonding tendencies. Transition metals show variable oxidation states because of partially filled d-orbitals, allowing flexible electron loss. Main group elements follow a predictable pattern based on valence electrons (e.g., +1 for alkali metals,...

Lanthanoids and actinoids are two series of f-block elements with distinct properties. Lanthanoids (atomic numbers 57–71) exhibit a +3 oxidation state and are known for their magnetic, optical, and catalytic applications. They are used in strong magnets, phosphors, and electronics. Actinoids (atomic numbers 89–103) have variable oxidation states and include radioactive elements like uranium and plutonium, crucial for nuclear energy and weaponry. While lanthanoids are relatively stable and le...

The d- and f-block elements, also known as transition and inner transition metals, have numerous applications due to their unique properties. Transition metals (d-block) like iron, copper, and titanium are used in construction, electronics, and catalysis. Platinum and palladium are essential in catalytic converters. f-block elements, primarily lanthanides, are used in strong magnets, lasers, and phosphors in LED screens. Actinides like uranium and plutonium play key roles in nuclear energy. Thei...

Lanthanoids (lanthanides) are 14 elements from cerium (Ce) to lutetium (Lu) in the periodic table, following lanthanum (La). They belong to the f-block and have a general electronic configuration of [Xe] 4f¹⁻¹⁴ 5d⁰⁻¹ 6s². Due to the poor shielding of 4f electrons, they exhibit the lanthanoid contraction—a gradual decrease in atomic and ionic sizes across the series. They show variable oxidation states (mainly +3) and have high reactivity, especially with water and acids. Lanthanoid...