Introduction to d-block and f-block Elements

d-block elements, also known as transition metals, include groups 3 to 12 on the periodic table. These elements are characterized by the filling of their d-orbitals, contributing to unique properties like variable oxidation states and complex formation.

Transition metals exhibit properties such as high melting points, magnetic behavior, and the ability to form colored compounds. Their d-electrons can absorb visible light, leading to characteristic colors used in dyes and pigments.

f-block elements are known as lanthanides and actinides, occupying the two rows below the main periodic table. These elements have partially filled f-orbitals, leading to complex electronic configurations and unique chemical behaviors.

Lanthanides (atomic numbers 57-71) are often called rare earth elements. Despite their name, they are relatively abundant in the Earth's crust. They are crucial in modern technology, found in smartphones, electric vehicles, and renewable energy systems.

Actinides (atomic numbers 89-103) are mostly radioactive. Uranium and plutonium are well-known for their use in nuclear reactors and weapons. Lesser-known actinides like americium are used in smoke detectors, showcasing their practical applications.

Despite gold's resistance to corrosion and oxidation, it can dissolve in a mixture of nitric and hydrochloric acids, known as aqua regia, producing chloroauric acid.