Sc (Z = 21) is a transition element but Zn (Z = 30) is not because
[A] Both Sc and Zn do not exhibit variable oxidation states
[B] Both Sc3+ and Zn2+ ions are colourless and form white compounds
[C] In case of Sc, 3d orbitals are partially filled but in Zn these are filled
[D] Last electron is assumed to be added to 4s level in case of Zn
Iron exhibits + 2 and + 3 oxidation states . Which of the following statement about iron is incorrect ?
[A] Ferrous oxide is more basic in nature than the ferric oxide
[B] Ferrous compounds are relatively more ionic than the corresponding ferric compounds
[C] Ferrous compounds are more easily hydrolysed than the corresponding ferric compounds
[D] Ferrous compounds are less volatile than the corresponding ferric compounds
The increasing order of the ionic radii of the given isoelectronic species is
[A] Cl–, Ca2+, K+, S2-
[B] S2-, CL–, ca2+, K+
[C] Ca2+, K+, Cl–, S2-
[D] K+, S2-, Ca2+, Cl –
Among the following inert gas elements, the element that shows highest chemical reactivity is
Which one of the following sets contribute to the global warming ?
[A] H2, NO2, SO2
[B] SO2, SO3, O2
[C] N2, C2H6, SO3
[D] CO2, CH4, CFCs
Elements A, B and C belong to the same period in the long form of the periodic table. The nature of the oxides of A, B and C is Amphoteric, basic and acidic respectively. The correct order of the atomic number of these elements is
Which one of the following is the correct order of the size of the ions ?
[A] O2- > F–> Mg2+> Na+
[B] Na+> Mg2+> F–> O2–
[C] O2– > F– > Na+ > Mg2+
[D] Mg2+ > Na+ > F– > O2+
Which of the following orders of ionic radii is correctly represented ?
[C] Al3+> Mg2+> N3-
Be2+ is isoelectronic with which of the following ions ?
Magnetic moment 2.83 is given by which of the following ions ?
(At. nos. Ti = 22, Cr = 24, Mn = 25, Ni = 28)
Reason of lanthanoid contraction is
[A] Increasing nuclear charge
[B] Decreasing nuclear charge
[C] decreasing screen .effect
[D] Negligible screening effect of T orbitals
Alkali metals have negative reduction potential and hence they behave as
[A] Oxidising agents
[B] Lewis bases
[C] Reducing agents
The electronic configuration of Cu2+ ion is
[A] [Ar] 3d8 4s1
[B] [Ar] 3d9 4s0
[C] [Ar] 3d7 4s2
[D] [Ar] 3d8 4S0
In which of the following options the order of arrangement does not agree with variation of property indicted against it?
[A] Al3+ < Mg2+ < Na+ < F– (increasing ionic size)