Flashcards for JEE Chemistry - D and F - Block Elements Class 12

 Page 1


D and F - Block Elements
Flash cards
Page 2


D and F - Block Elements
Flash cards
The transition elements may be defined as elements whose atoms or simple ions in
their most common oxidation state contain partially filled d-orbitals. This definition
does not cover zinc, cadmium and mercury.
However, these are studied with transition elements.
The general electronic configuration of these elements is (n – 1)d
1 – 10
ns
0 – 2
.
Page 3


D and F - Block Elements
Flash cards
The transition elements may be defined as elements whose atoms or simple ions in
their most common oxidation state contain partially filled d-orbitals. This definition
does not cover zinc, cadmium and mercury.
However, these are studied with transition elements.
The general electronic configuration of these elements is (n – 1)d
1 – 10
ns
0 – 2
.
ATOMIC AND PHYSICAL PROPERTIES (Continued)
The important properties of the transition metals are given below :
1. Metallic Character
(a) Transition elements exhibit good mechanical properties, i.e, they are hard,
malleable and ductile. They have high enthalpies of atomization, high melting and
boiling points, they have high thermal and electrical conductivity as well as lustre.
(b) Their mechanical properties and high melting as well as boiling points indicate
the presence of strong metallic bond.
Page 4


D and F - Block Elements
Flash cards
The transition elements may be defined as elements whose atoms or simple ions in
their most common oxidation state contain partially filled d-orbitals. This definition
does not cover zinc, cadmium and mercury.
However, these are studied with transition elements.
The general electronic configuration of these elements is (n – 1)d
1 – 10
ns
0 – 2
.
ATOMIC AND PHYSICAL PROPERTIES (Continued)
The important properties of the transition metals are given below :
1. Metallic Character
(a) Transition elements exhibit good mechanical properties, i.e, they are hard,
malleable and ductile. They have high enthalpies of atomization, high melting and
boiling points, they have high thermal and electrical conductivity as well as lustre.
(b) Their mechanical properties and high melting as well as boiling points indicate
the presence of strong metallic bond.
Metallic	Character	of	Transition	Elements
Page 5


D and F - Block Elements
Flash cards
The transition elements may be defined as elements whose atoms or simple ions in
their most common oxidation state contain partially filled d-orbitals. This definition
does not cover zinc, cadmium and mercury.
However, these are studied with transition elements.
The general electronic configuration of these elements is (n – 1)d
1 – 10
ns
0 – 2
.
ATOMIC AND PHYSICAL PROPERTIES (Continued)
The important properties of the transition metals are given below :
1. Metallic Character
(a) Transition elements exhibit good mechanical properties, i.e, they are hard,
malleable and ductile. They have high enthalpies of atomization, high melting and
boiling points, they have high thermal and electrical conductivity as well as lustre.
(b) Their mechanical properties and high melting as well as boiling points indicate
the presence of strong metallic bond.
Metallic	Character	of	Transition	Elements
ATOMIC AND PHYSICAL PROPERTIES (Continued)
2. Ionisation Energies
(a) The ionisation energies of transition metals increases as we move across each 
series though not quite regularly.
(b) It is evident that first ionisation energies of most of the 5d elements are higher 
than those of 3d and 4d-elements. This is due to the fact that the outer valence 
electrons of 5d-elements experience greater effective nuclear charge due to poor 
shielding of the nucleus by 4f-electrons.
3. Electrode Potential
In general, transition elements have low negative values of standard reduction 
electrode potential due to high ionisation energies, high heat of sublimation which 
are more than offset with large heats of hydration. Consequently, transition elements 
are weak reducing agents and are less reactive than s-block elements.