Which of the following statements is most appropriate for transition elements?

Question

Question

This question was previously asked in

RRB ALP CBT I 30 Aug 2018 Shift 3 Official Paper

Answer 1

The correct answer is Two of their outermost shells are incomplete.

Key Points

Transition metals are defined as those elements that have partially filled (two outermost shells are incomplete) d-orbitals. Hence option 3 is correct.
- d-block elements are elements that have the ability to form stable cations with an incompletely filled d-orbital.
The electronic configuration of d-block elements is (n-1)d^1-10ns^1-2where (n–1) stands for the inner d orbitals which may have one to ten electrons and the outermost ns orbital may have one or two electrons.
All d-block elements (groups 3-12) are transition elements except Zinc, Cadmium, and Mercury.
- The electronic configurations of Zinc (Zn), Cadmium (Cd), and Mercury (Hg) are represented by the general formula (n-1)d¹⁰ns²
- Even the f-block elements comprising the lanthanides and the actinides can be considered transition metals.
The valence shell of the transition element consists of (n−1)d electrons. For transition elements, the last electron (differentiating electron) enters the d orbital of the penultimate shell i.e. (n−1)d orbital where n is the outermost shell.

Additional Information

All the transition elements display typical metallic properties such as high tensile strength, ductility, malleability, high thermal and electrical conductivity, and metallic luster with the exceptions of Zn, Cd, and Hg.
In any row, the melting points of these metals rise to a maximum at d⁵ except for anomalous values of Manganese (Mn) and Technitium (Tc) and fall regularly as the atomic number increases.
- Technitium (Z = 43) is a transition metal and is solid at room temperature. Manganese atomic number, Z = 25, and is a transition metal.
Transition elements exhibit higher enthalpies of atomization because of a large number of unpaired electrons in their atoms they have stronger interatomic interaction and hence stronger bonding between atoms resulting in higher enthalpies of atomization.