Introduction
What is this section about?
This section introduces the transition metals (d-block) and inner transition metals (f-block) of the periodic table.
Simple Explanation:
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d-block (Transition Metals):
- Location: Groups 3-12 of the periodic table.
- Electron Configuration: Characterized by the progressive filling of d orbitals.
- Series: There are four transition metal series:
- 3d series: Scandium (Sc) to Zinc (Zn)
- 4d series: Yttrium (Y) to Cadmium (Cd)
- 5d series: Lanthanum (La) and Hafnium (Hf) to Mercury (Hg)
- 6d series: Actinium (Ac) and Rutherfordium (Rf) to Copernicium (Cn)
- Definition: According to IUPAC, a transition metal is an element that has an incomplete d subshell in its neutral atom or in its ions.
- Exception: Zinc (Zn), Cadmium (Cd), and Mercury (Hg) are in the d-block but are not considered true transition metals because they have a full d<sup>10</sup> configuration in both their ground state and common oxidation states. However, they are studied alongside the transition metals because they are the end members of their respective series.
- Key Feature: The presence of partially filled d orbitals is what gives transition metals their unique properties.
- Examples: Silver (Ag), gold (Au), platinum (Pt), iron (Fe), copper (Cu), and titanium (Ti).
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f-block (Inner Transition Metals):
- Location: Placed in a separate panel at the bottom of the periodic table.
- Electron Configuration: Characterized by the progressive filling of 4f and 5f orbitals.
- Series: There are two series of inner transition metals:
- 4f series: Cerium (Ce) to Lutetium (Lu) – known as Lanthanoids.
- 5f series: Thorium (Th) to Lawrencium (Lr) – known as Actinoids.
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Why "Transition"? The name "transition metals" originally came from the fact that their properties were "transitional" between the very reactive s-block metals (like sodium and potassium) and the less metallic p-block elements (like chlorine and oxygen).
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Study Focus: This unit will focus on the electronic configurations, occurrence, general properties, and trends in the properties of the first-row (3d) transition metals, along with the preparation and properties of some important compounds. It will also cover some general aspects of the inner transition metals.
Simple Conclusion:
The transition metals (d-block) are elements with partially filled d orbitals, giving them unique properties. The inner transition metals (f-block) are elements with partially filled f orbitals. These elements are important in various industries and applications. Zinc, cadmium, and mercury, although in the d-block, are not considered true transition metals due to their filled d orbitals.