General Properties of Transition Elements
Variable oxidation states, colour, magnetic behaviour, catalytic property and alloy formation. (Chemistry › d- and f-Block Elements, NEET UG syllabus.)
What is General Properties of Transition Elements?
Elements whose atoms or common ions have partially filled d-orbitals.
Key formula / rule: Spin-only Magnetic Moment
Key points
- Explain the reasons for variable oxidation states in transition elements.
- Describe the origin of colour in transition metal compounds.
- Differentiate between paramagnetic, diamagnetic, and ferromagnetic substances.
- Calculate the spin-only magnetic moment for transition metal ions.
Common exam trap
Assuming all transition metal compounds are coloured (e.g., Sc3+, Zn2+, Cu+ are colourless).
Definitions
- Term
Transition Elements
- Meaning
Elements whose atoms or common ions have partially filled d-orbitals.
- Term
Paramagnetism
- Meaning
The property of substances that are weakly attracted by a magnetic field due to the presence of unpaired electrons.
- Term
Diamagnetism
- Meaning
The property of substances that are weakly repelled by a magnetic field due to the presence of only paired electrons.
- Term
Ferromagnetism
- Meaning
A strong form of paramagnetism, where substances are strongly attracted by a magnetic field and can retain magnetism even after the external field is removed.
- Term
d-d Transition
- Meaning
The excitation of an electron from a lower energy d-orbital to a higher energy d-orbital within the same subshell, typically by absorbing energy from visible light.
- Term
Catalysis
- Meaning
The process of increasing the rate of a chemical reaction by adding a substance (catalyst) that is not consumed in the overall reaction.
Learning objectives
Explain the reasons for variable oxidation states in transition elements.
Describe the origin of colour in transition metal compounds.
Differentiate between paramagnetic, diamagnetic, and ferromagnetic substances.
Calculate the spin-only magnetic moment for transition metal ions.
Explain the catalytic properties of transition metals and their compounds.
Understand why transition metals readily form alloys.
Formulae
- Name
Spin-only Magnetic Moment
- Note
Where 'n' is the number of unpaired electrons and μ is in Bohr Magnetons (BM).
- Expression
μ = √n(n+2)
Prerequisites
Electronic configuration of elements (especially d-block elements).
Basic understanding of atomic structure and orbitals.
Periodic trends (atomic size, ionization enthalpy).
Concept of oxidation states.
Basic knowledge of chemical bonding.
Common mistakes
Assuming all transition metal compounds are coloured (e.g., Sc3+, Zn2+, Cu+ are colourless).
Confusing paramagnetism with diamagnetism or ferromagnetism.
Incorrectly applying the magnetic moment formula or miscounting unpaired electrons.
Not linking variable oxidation states to catalytic activity.
Forgetting the role of similar atomic sizes in alloy formation.
Keywords
Transition elements
d-block
variable oxidation states
colour
d-d transition
paramagnetism
diamagnetism
ferromagnetism
magnetic moment
catalysis
alloys
unpaired electrons
electronic configuration
Practice preview
Most transition metal compounds are coloured. This property is primarily due to:…
easy
Transition metals readily form alloys with other transition metals because of their:…
medium
Which of the following transition metal ions is both diamagnetic and colourless in aqueous solution?…
hard