General electronic configuration of lanthanides are
(n-2) f1-14(n-1)s2 p6d0-1ns2
(n-2) f10-14(n-1)d0-1ns2
(n-2) f0-14 (n-1)d10ns2
(n-2)d0-1 (n-1) f1-14 ns2
The common oxidation states of Ti are
+2, +3
+3, +4
3, -4
+2, +3, +4
Lanthanides are
14 elements in the sixth period (at no = 90 to 103) that are filling 4f sub-level
14 elements in the seventh period (at no = 90 to 103) that are filling 5f sub-level
14 elements in the sixth period (at no = 58 to 71) that are filling 4 f sub-level
14 elements in the seventh period (at no = 58 to 71) that are filling 4f sub-level.
Which one of the following forms a colourless solution in aqueous medium ?
V3+
Cr3+
Ti3+
Sc3+
The lanthanide contraction is responsible for the fact that
Zr and Yt have about the same radius
Zr and Nb have similar oxidation state
Zr and Hf have about the same radius
Zr and Zn have the same oxidation state
Identify the incorrect statement among the following.
There is a decrease in the radii of the atoms or ions as one proceeds from La or Lu.
Lanthanide contraction is the accumulation of successive shrinkages
As a result of lanthanide contraction, the properties of 4d series of the transition elements have no similarities with the 5d series of elements.
Shielding power of 4f electrons is quite weak
Which one of the following characteristics of the transition metals is associated with their catalytic activity ?
Colour of hydrated ions
Variable oxidation states
High enthalpy of atomisation
Paramagnetic behaviour
Which of the following elements is responsible for oxidation of water to O2 in biological processes ?
Fe
Cu
Mn
Mo
K2Cr2O7 on heating with aqueous NaOH gives
CrO42-
Cr(OH)3
Cr(OH)2
