The smaller the atomic size, larger is the value of IP. Further the atoms having half-filled or fully filled orbitals are comparatively more stable, hence more energy is required to remove the electron from such atoms.
JEE - 2017
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313354
The ionisation energy of nitrogen is larger than that of oxygen because of
1 greater attraction of electrons by the nucleus
2 the size of the nitrogen atom being smaller
3 the half-filled p-orbitals possess extra stability
4 greater penetration effect.
Explanation:
Electronic configuration of \({\rm{N}} = 1{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{p}}^{\rm{3}}}\) Electronic configuration of \({\rm{O}} = {\rm{1}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{p}}^{\rm{4}}}\) Since, half - filled p-orbital is more stable thus, it is very difficult to remove an electron from it hence, N has greater ionisation energy than O .
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313355
The ionisation energy of sodium is \({\rm{495}}\,{\rm{kJ}}\,{\rm{mo}}{{\rm{l}}^{{\rm{ - 1}}}}{\rm{.}}\) How much energy is needed to convert atoms present in 2.3 mg of sodium into sodium ions
1 4.95 J
2 49.5 J
3 495 J
4 0.495 J
Explanation:
Ionization energy of sodium = 495 kJ/mol Number of moles of sodium convert to sodium ions \({\rm{ = }}\frac{{{\rm{2}}{\rm{.3 \times 1}}{{\rm{0}}^{{\rm{ - 3}}}}}}{{{\rm{23}}}}{\rm{ = 1}}{{\rm{0}}^{{\rm{ - 4}}}}\,{\rm{moles}}\) 1 moles require energy is 495 kJ/mol \({\rm{1}}{{\rm{0}}^{{\rm{ - 4}}}}\) moles require energy is \({\rm{495 \times 1}}{{\rm{0}}^{\rm{3}}}{\rm{ \times 1}}{{\rm{0}}^{{\rm{ - 4}}}}\,{\rm{J}}\,{\rm{ = }}\,{\rm{49}}{\rm{.5}}\,{\rm{J}}\)
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313356
Among the following, the third ionisation energy is highest for
1 magnesium
2 boron
3 beryllium
4 aluminium
Explanation:
The electronic configuration of the given elements is as follows: \(_{{\rm{12}}}{\rm{Mg}} = {\rm{[Ne]3}}{{\rm{s}}^{\rm{2}}}{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {{\mkern 1mu} _{\rm{5}}}\;{\rm{B}} = {\rm{[He]2}}{{\rm{s}}^{\rm{2}}}{\rm{,2}}{{\rm{p}}^{\rm{1}}}\) \(_{\rm{4}}{\rm{Be}} = {\rm{[He]2}}{{\rm{s}}^{\rm{2}}}{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {{\mkern 1mu} _{{\rm{13}}}}{\rm{Al}} = [{\rm{Ne]3}}{{\rm{s}}^{\rm{2}}}{\rm{,3}}{{\rm{p}}^{\rm{1}}}\) From the electronic configuration, it is clear that third ionisation energy of \(\mathrm{Mg}\) and \(\mathrm{Be}\) is higher than that of \(\mathrm{Al}\) and \(\mathrm{B}\) In them, the third electron has to be removed from the stable inert gas configuration. Between \(\mathrm{Mg}\) and, Be third IE of Be is high because of its smaller size than Mg as both lie in the same group.
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313357
Which of the following represents the correct order of increasing first ionisation enthalpy for Ca, Ba, S, Se and Ar?
1 Ca < S < Ba < Se < Ar
2 S < Se < Ca < Ba < Ar
3 Ba < Ca < Se < S < Ar
4 Ca < Ba < S < Se < Ar
Explanation:
On moving down, a group size increases hence ionisation enthalpy decreases, hence Se < S and Ba < Ca. Further, Ar being an inert gas has maximum IE.
The smaller the atomic size, larger is the value of IP. Further the atoms having half-filled or fully filled orbitals are comparatively more stable, hence more energy is required to remove the electron from such atoms.
JEE - 2017
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313354
The ionisation energy of nitrogen is larger than that of oxygen because of
1 greater attraction of electrons by the nucleus
2 the size of the nitrogen atom being smaller
3 the half-filled p-orbitals possess extra stability
4 greater penetration effect.
Explanation:
Electronic configuration of \({\rm{N}} = 1{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{p}}^{\rm{3}}}\) Electronic configuration of \({\rm{O}} = {\rm{1}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{p}}^{\rm{4}}}\) Since, half - filled p-orbital is more stable thus, it is very difficult to remove an electron from it hence, N has greater ionisation energy than O .
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313355
The ionisation energy of sodium is \({\rm{495}}\,{\rm{kJ}}\,{\rm{mo}}{{\rm{l}}^{{\rm{ - 1}}}}{\rm{.}}\) How much energy is needed to convert atoms present in 2.3 mg of sodium into sodium ions
1 4.95 J
2 49.5 J
3 495 J
4 0.495 J
Explanation:
Ionization energy of sodium = 495 kJ/mol Number of moles of sodium convert to sodium ions \({\rm{ = }}\frac{{{\rm{2}}{\rm{.3 \times 1}}{{\rm{0}}^{{\rm{ - 3}}}}}}{{{\rm{23}}}}{\rm{ = 1}}{{\rm{0}}^{{\rm{ - 4}}}}\,{\rm{moles}}\) 1 moles require energy is 495 kJ/mol \({\rm{1}}{{\rm{0}}^{{\rm{ - 4}}}}\) moles require energy is \({\rm{495 \times 1}}{{\rm{0}}^{\rm{3}}}{\rm{ \times 1}}{{\rm{0}}^{{\rm{ - 4}}}}\,{\rm{J}}\,{\rm{ = }}\,{\rm{49}}{\rm{.5}}\,{\rm{J}}\)
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313356
Among the following, the third ionisation energy is highest for
1 magnesium
2 boron
3 beryllium
4 aluminium
Explanation:
The electronic configuration of the given elements is as follows: \(_{{\rm{12}}}{\rm{Mg}} = {\rm{[Ne]3}}{{\rm{s}}^{\rm{2}}}{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {{\mkern 1mu} _{\rm{5}}}\;{\rm{B}} = {\rm{[He]2}}{{\rm{s}}^{\rm{2}}}{\rm{,2}}{{\rm{p}}^{\rm{1}}}\) \(_{\rm{4}}{\rm{Be}} = {\rm{[He]2}}{{\rm{s}}^{\rm{2}}}{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {{\mkern 1mu} _{{\rm{13}}}}{\rm{Al}} = [{\rm{Ne]3}}{{\rm{s}}^{\rm{2}}}{\rm{,3}}{{\rm{p}}^{\rm{1}}}\) From the electronic configuration, it is clear that third ionisation energy of \(\mathrm{Mg}\) and \(\mathrm{Be}\) is higher than that of \(\mathrm{Al}\) and \(\mathrm{B}\) In them, the third electron has to be removed from the stable inert gas configuration. Between \(\mathrm{Mg}\) and, Be third IE of Be is high because of its smaller size than Mg as both lie in the same group.
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313357
Which of the following represents the correct order of increasing first ionisation enthalpy for Ca, Ba, S, Se and Ar?
1 Ca < S < Ba < Se < Ar
2 S < Se < Ca < Ba < Ar
3 Ba < Ca < Se < S < Ar
4 Ca < Ba < S < Se < Ar
Explanation:
On moving down, a group size increases hence ionisation enthalpy decreases, hence Se < S and Ba < Ca. Further, Ar being an inert gas has maximum IE.
The smaller the atomic size, larger is the value of IP. Further the atoms having half-filled or fully filled orbitals are comparatively more stable, hence more energy is required to remove the electron from such atoms.
JEE - 2017
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313354
The ionisation energy of nitrogen is larger than that of oxygen because of
1 greater attraction of electrons by the nucleus
2 the size of the nitrogen atom being smaller
3 the half-filled p-orbitals possess extra stability
4 greater penetration effect.
Explanation:
Electronic configuration of \({\rm{N}} = 1{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{p}}^{\rm{3}}}\) Electronic configuration of \({\rm{O}} = {\rm{1}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{p}}^{\rm{4}}}\) Since, half - filled p-orbital is more stable thus, it is very difficult to remove an electron from it hence, N has greater ionisation energy than O .
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313355
The ionisation energy of sodium is \({\rm{495}}\,{\rm{kJ}}\,{\rm{mo}}{{\rm{l}}^{{\rm{ - 1}}}}{\rm{.}}\) How much energy is needed to convert atoms present in 2.3 mg of sodium into sodium ions
1 4.95 J
2 49.5 J
3 495 J
4 0.495 J
Explanation:
Ionization energy of sodium = 495 kJ/mol Number of moles of sodium convert to sodium ions \({\rm{ = }}\frac{{{\rm{2}}{\rm{.3 \times 1}}{{\rm{0}}^{{\rm{ - 3}}}}}}{{{\rm{23}}}}{\rm{ = 1}}{{\rm{0}}^{{\rm{ - 4}}}}\,{\rm{moles}}\) 1 moles require energy is 495 kJ/mol \({\rm{1}}{{\rm{0}}^{{\rm{ - 4}}}}\) moles require energy is \({\rm{495 \times 1}}{{\rm{0}}^{\rm{3}}}{\rm{ \times 1}}{{\rm{0}}^{{\rm{ - 4}}}}\,{\rm{J}}\,{\rm{ = }}\,{\rm{49}}{\rm{.5}}\,{\rm{J}}\)
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313356
Among the following, the third ionisation energy is highest for
1 magnesium
2 boron
3 beryllium
4 aluminium
Explanation:
The electronic configuration of the given elements is as follows: \(_{{\rm{12}}}{\rm{Mg}} = {\rm{[Ne]3}}{{\rm{s}}^{\rm{2}}}{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {{\mkern 1mu} _{\rm{5}}}\;{\rm{B}} = {\rm{[He]2}}{{\rm{s}}^{\rm{2}}}{\rm{,2}}{{\rm{p}}^{\rm{1}}}\) \(_{\rm{4}}{\rm{Be}} = {\rm{[He]2}}{{\rm{s}}^{\rm{2}}}{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {{\mkern 1mu} _{{\rm{13}}}}{\rm{Al}} = [{\rm{Ne]3}}{{\rm{s}}^{\rm{2}}}{\rm{,3}}{{\rm{p}}^{\rm{1}}}\) From the electronic configuration, it is clear that third ionisation energy of \(\mathrm{Mg}\) and \(\mathrm{Be}\) is higher than that of \(\mathrm{Al}\) and \(\mathrm{B}\) In them, the third electron has to be removed from the stable inert gas configuration. Between \(\mathrm{Mg}\) and, Be third IE of Be is high because of its smaller size than Mg as both lie in the same group.
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313357
Which of the following represents the correct order of increasing first ionisation enthalpy for Ca, Ba, S, Se and Ar?
1 Ca < S < Ba < Se < Ar
2 S < Se < Ca < Ba < Ar
3 Ba < Ca < Se < S < Ar
4 Ca < Ba < S < Se < Ar
Explanation:
On moving down, a group size increases hence ionisation enthalpy decreases, hence Se < S and Ba < Ca. Further, Ar being an inert gas has maximum IE.
The smaller the atomic size, larger is the value of IP. Further the atoms having half-filled or fully filled orbitals are comparatively more stable, hence more energy is required to remove the electron from such atoms.
JEE - 2017
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313354
The ionisation energy of nitrogen is larger than that of oxygen because of
1 greater attraction of electrons by the nucleus
2 the size of the nitrogen atom being smaller
3 the half-filled p-orbitals possess extra stability
4 greater penetration effect.
Explanation:
Electronic configuration of \({\rm{N}} = 1{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{p}}^{\rm{3}}}\) Electronic configuration of \({\rm{O}} = {\rm{1}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{p}}^{\rm{4}}}\) Since, half - filled p-orbital is more stable thus, it is very difficult to remove an electron from it hence, N has greater ionisation energy than O .
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313355
The ionisation energy of sodium is \({\rm{495}}\,{\rm{kJ}}\,{\rm{mo}}{{\rm{l}}^{{\rm{ - 1}}}}{\rm{.}}\) How much energy is needed to convert atoms present in 2.3 mg of sodium into sodium ions
1 4.95 J
2 49.5 J
3 495 J
4 0.495 J
Explanation:
Ionization energy of sodium = 495 kJ/mol Number of moles of sodium convert to sodium ions \({\rm{ = }}\frac{{{\rm{2}}{\rm{.3 \times 1}}{{\rm{0}}^{{\rm{ - 3}}}}}}{{{\rm{23}}}}{\rm{ = 1}}{{\rm{0}}^{{\rm{ - 4}}}}\,{\rm{moles}}\) 1 moles require energy is 495 kJ/mol \({\rm{1}}{{\rm{0}}^{{\rm{ - 4}}}}\) moles require energy is \({\rm{495 \times 1}}{{\rm{0}}^{\rm{3}}}{\rm{ \times 1}}{{\rm{0}}^{{\rm{ - 4}}}}\,{\rm{J}}\,{\rm{ = }}\,{\rm{49}}{\rm{.5}}\,{\rm{J}}\)
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313356
Among the following, the third ionisation energy is highest for
1 magnesium
2 boron
3 beryllium
4 aluminium
Explanation:
The electronic configuration of the given elements is as follows: \(_{{\rm{12}}}{\rm{Mg}} = {\rm{[Ne]3}}{{\rm{s}}^{\rm{2}}}{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {{\mkern 1mu} _{\rm{5}}}\;{\rm{B}} = {\rm{[He]2}}{{\rm{s}}^{\rm{2}}}{\rm{,2}}{{\rm{p}}^{\rm{1}}}\) \(_{\rm{4}}{\rm{Be}} = {\rm{[He]2}}{{\rm{s}}^{\rm{2}}}{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {{\mkern 1mu} _{{\rm{13}}}}{\rm{Al}} = [{\rm{Ne]3}}{{\rm{s}}^{\rm{2}}}{\rm{,3}}{{\rm{p}}^{\rm{1}}}\) From the electronic configuration, it is clear that third ionisation energy of \(\mathrm{Mg}\) and \(\mathrm{Be}\) is higher than that of \(\mathrm{Al}\) and \(\mathrm{B}\) In them, the third electron has to be removed from the stable inert gas configuration. Between \(\mathrm{Mg}\) and, Be third IE of Be is high because of its smaller size than Mg as both lie in the same group.
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313357
Which of the following represents the correct order of increasing first ionisation enthalpy for Ca, Ba, S, Se and Ar?
1 Ca < S < Ba < Se < Ar
2 S < Se < Ca < Ba < Ar
3 Ba < Ca < Se < S < Ar
4 Ca < Ba < S < Se < Ar
Explanation:
On moving down, a group size increases hence ionisation enthalpy decreases, hence Se < S and Ba < Ca. Further, Ar being an inert gas has maximum IE.
The smaller the atomic size, larger is the value of IP. Further the atoms having half-filled or fully filled orbitals are comparatively more stable, hence more energy is required to remove the electron from such atoms.
JEE - 2017
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313354
The ionisation energy of nitrogen is larger than that of oxygen because of
1 greater attraction of electrons by the nucleus
2 the size of the nitrogen atom being smaller
3 the half-filled p-orbitals possess extra stability
4 greater penetration effect.
Explanation:
Electronic configuration of \({\rm{N}} = 1{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{p}}^{\rm{3}}}\) Electronic configuration of \({\rm{O}} = {\rm{1}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{s}}^{\rm{2}}}{\rm{2}}{{\rm{p}}^{\rm{4}}}\) Since, half - filled p-orbital is more stable thus, it is very difficult to remove an electron from it hence, N has greater ionisation energy than O .
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313355
The ionisation energy of sodium is \({\rm{495}}\,{\rm{kJ}}\,{\rm{mo}}{{\rm{l}}^{{\rm{ - 1}}}}{\rm{.}}\) How much energy is needed to convert atoms present in 2.3 mg of sodium into sodium ions
1 4.95 J
2 49.5 J
3 495 J
4 0.495 J
Explanation:
Ionization energy of sodium = 495 kJ/mol Number of moles of sodium convert to sodium ions \({\rm{ = }}\frac{{{\rm{2}}{\rm{.3 \times 1}}{{\rm{0}}^{{\rm{ - 3}}}}}}{{{\rm{23}}}}{\rm{ = 1}}{{\rm{0}}^{{\rm{ - 4}}}}\,{\rm{moles}}\) 1 moles require energy is 495 kJ/mol \({\rm{1}}{{\rm{0}}^{{\rm{ - 4}}}}\) moles require energy is \({\rm{495 \times 1}}{{\rm{0}}^{\rm{3}}}{\rm{ \times 1}}{{\rm{0}}^{{\rm{ - 4}}}}\,{\rm{J}}\,{\rm{ = }}\,{\rm{49}}{\rm{.5}}\,{\rm{J}}\)
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313356
Among the following, the third ionisation energy is highest for
1 magnesium
2 boron
3 beryllium
4 aluminium
Explanation:
The electronic configuration of the given elements is as follows: \(_{{\rm{12}}}{\rm{Mg}} = {\rm{[Ne]3}}{{\rm{s}}^{\rm{2}}}{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {{\mkern 1mu} _{\rm{5}}}\;{\rm{B}} = {\rm{[He]2}}{{\rm{s}}^{\rm{2}}}{\rm{,2}}{{\rm{p}}^{\rm{1}}}\) \(_{\rm{4}}{\rm{Be}} = {\rm{[He]2}}{{\rm{s}}^{\rm{2}}}{\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {\mkern 1mu} {{\mkern 1mu} _{{\rm{13}}}}{\rm{Al}} = [{\rm{Ne]3}}{{\rm{s}}^{\rm{2}}}{\rm{,3}}{{\rm{p}}^{\rm{1}}}\) From the electronic configuration, it is clear that third ionisation energy of \(\mathrm{Mg}\) and \(\mathrm{Be}\) is higher than that of \(\mathrm{Al}\) and \(\mathrm{B}\) In them, the third electron has to be removed from the stable inert gas configuration. Between \(\mathrm{Mg}\) and, Be third IE of Be is high because of its smaller size than Mg as both lie in the same group.
CHXI03:CLASSIFICATION OF ELEMENTS AND PERIODICITY IN PROPERTIES
313357
Which of the following represents the correct order of increasing first ionisation enthalpy for Ca, Ba, S, Se and Ar?
1 Ca < S < Ba < Se < Ar
2 S < Se < Ca < Ba < Ar
3 Ba < Ca < Se < S < Ar
4 Ca < Ba < S < Se < Ar
Explanation:
On moving down, a group size increases hence ionisation enthalpy decreases, hence Se < S and Ba < Ca. Further, Ar being an inert gas has maximum IE.
