The formation of the oxide ion O2- (g), from oxygen atom requires first an exothermic and then an endothermic step as shown below,
Thus, process of formation of O2- in gas phase is unfavorable even though O2- is isoelectronic with neon. It is due to the fact that :
1. Electron repulsion outweighs the stability gained by achieving noble gas configuration .
2. ion has comparatively smaller size than oxygen atom.
3. Oxygen is more electronegative.
4. Addition of electron in oxygen result in large size of the ion .
The species Ar, K+ and Ca2+ contain the same number of electrons. In which order do their radii increase?
1. Ar < K+ < Ca2+
2. Ca2+ < Ar < K+
3. Ca2+ < K+ < Ar
4. K+ < Ar < Ca2+
Which of the following order of ionic radii is correctly represented?
Be2+ is isoelectronic with which of the following ions?
What is the value of electron gain enthalpy of Na+ if IE1 of Na = 5.1 eV?
1. + 10.2 eV
2. –5.1 eV
3. –10.2 eV
4. + 2.55 eV
The correct order of the decreasing ionic radii among the following isoelectronic species is:
Which of the following represents the correct order of increasing electron affinity for the elements, O, S, F and Cl ?
1. Cl < F < O < S
2. O < S < F < Cl
3. F < S < O < Cl
4. S < O < Cl < F
Among the elements Ca, Mg, P and Cl, the correct order of increasing atomic radii is -
1. Cl < P < Mg < Ca
2. P < Cl < Ca < Mg
3. Ca < Mg < P < Cl
4. Mg < Ca < Cl < P
Amongst the elements with following electronic configurations, which one of them may have the highest ionisation energy ?
1. Cr > Mn > V > Ti
2. V > Mn > Cr > Ti
3. Mn > Cr > Ti > V
4. Ti > V > Cr > Mn