Transition Metals Overview

Transition Metals

• Transition metals are elements with partially filled d orbitals.
• They display a wide range of oxidation states.
• They often act as catalysts.
• They exhibit varied magnetic properties.
• Many form interstitial compounds.
• They readily form alloys.

Electronic Configuration

• Transition metals generally have (n-1)d electrons and ns electrons.
• Electronic configurations vary across the d-block.

Occurrence and Characteristics

• Transition metals are found in diverse minerals and ores.
• They display variable oxidation states.
• They are typically hard and strong.
• They have relatively high melting and boiling points.

General Trends in Properties of First-Row Transition Metals

Metallic Character

• Metallic character generally decreases across the period.
• This is due to increasing effective nuclear charge.

Ionization Enthalpy

• Ionization enthalpy generally increases across the period.
• There are some irregularities.
• This is due to the electron shielding effect.

Oxidation States

• Transition metals exhibit a variety of oxidation states.
• The common oxidation states are +2 and +3.
• Greater number of different oxidation states are shown in the middle.
• The highest oxidation states are shown at the right in the periodic table

Ionic Radii

• Ionic radii generally decrease across the series.
• This is due to the increase in effective nuclear charge.

Color

• Many transition metal compounds are colored due to d-d transitions.
• Colour depends on the oxidation state and ligand.

Catalytic Property

• Transition metals and their compounds often act as good catalysts.
• This is due to their variable oxidation states and ability to form intermediate complexes.

Magnetic Properties

• Transition metal compounds exhibit various magnetic properties (paramagnetic, diamagnetic)
• This depends on the electronic configuration .

Interstitial Compounds

• Transition metals can form interstitial compounds.
• These compounds have non-metal atoms in the interstitial sites of the crystal lattice of the transition metal.

Alloy Formation

• Transition metals readily form alloys.
• Alloys have improved properties compared to individual elements.

Potassium Dichromate (K₂Cr₂O₇) and Potassium Permanganate (KMnO₄)

• Potassium Dichromate (K₂Cr₂O₇): Strong oxidizing agent, orange crystalline solid, used in various industrial applications.
• Potassium Permanganate (KMnO₄): Powerful oxidizing agent, deep purple crystalline solid, used as a disinfectant, oxidizing agent in chemical reactions.

Lanthanoids

Electronic Configuration

• Lanthanoids have the general electronic configuration [Xe] 4f^1-14 5d^0-1 6s².
• The 4f electrons are shielded internally from external influences.

Oxidation States

• The common oxidation state is +3.
• Other oxidation states are also observed but less frequently.

Chemical Reactivity

• Lanthanoids are moderately reactive metals.
• Their reactivity decreases slightly with increasing atomic number.

Lanthanoid Contraction

• Gradual decrease in the size of lanthanoid atoms with increasing atomic number. This results from the poor shielding effect of the 4f electrons.
• This decrease is important because it influences the properties of subsequent elements and compounds.
• This has impact on the properties of the transition metals.

Actinoids

Electronic Configuration

• Actinoids have the general electronic configuration [Rn] 5f^1-14 6d^0-1 7s².

Oxidation States

• Actinoids exhibit a wide range of oxidation states.
• The most common oxidation state is +3.
• Other high oxidation states (+4, +5,+6,+7) are also possible and are important from various research and industrial aspects.

Comparison with Lanthanoids

• Actinoids are more reactive than lanthanoids, showing greater variability in oxidation states.
• Actinoids are radioactive, unlike lanthanoids. (Important Note)
• Actinoid chemistry is more complex and less well understood.

Explore the fascinating world of transition metals, which are characterized by partially filled d orbitals and a wide range of oxidation states. This quiz covers their electronic configurations, occurrence, properties, and trends, such as metallic character and ionization enthalpy. Test your knowledge on these essential elements and their unique characteristics.