Q. No.Which of the following statements are true?
Choose the correct answer from the options given below:
| A. | Unlike Ga that has a very high melting point, Cs has a very low melting point. |
| B. | On Pauling scale, the electronegativity values of N and Cl are not the same. |
| C. | \(Ar, K^+, Cl^-, Ca^{2+}\) and \(S^{2-}\) are all isoelectronic species. |
| D. | The correct order of the first ionization enthalpies of Na, Mg, Al, and Si is Si > Al > Mg > Na |
| E. | The atomic radius of Cs is greater than that of Li and Rb . |
| 1. | C and D only |
| 2. | A, C and E only |
| 3. | A, B and E only |
| 4. | C and E only |
Subtopic: Ionization Energy (IE) | Electronegativity |
From NCERT
NEET - 2025
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Arrange the elements Li, Be, B, C, and N in increasing order of their first ionization enthalpies:
| 1. | Li < B < Be < C < N | 2. | Li < Be < C < B < N |
| 3. | Li < Be < N < B < C | 4. | Li < Be < B < C < N |
Subtopic: Ionization Energy (IE) |
75%
From NCERT
NEET - 2024
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NEET 2026 - Target Batch - Vital
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NEET 2026 - Target Batch - Vital
Identify the incorrect statement:
| 1. | The oxidation state and coordination number (or covalency) of \(\mathrm{Al}\) in\( \left[\mathrm{AlCl}\left(\mathrm{{H}_2 {O}}\right)_5\right]^{2+} \) are +3 and 6, respectively. |
| 2. | \(\mathrm{Na}_2 \mathrm{O}\) is a basic oxide and \(\mathrm{Cl}_2 \mathrm{O}_7\) is an acidic oxide |
| 3. | The following four species are called isoelectronic species: \( \mathrm{O}^{2-}, \mathrm{F}^{-}, \mathrm{Na}^{+} \mathrm{and}~ \mathrm{Mg}^{2+}\) |
| 4. | Among the four species \(\mathrm{Mg}, \mathrm{Al}, \mathrm{Mg}^{2+}\) and \(\mathrm{A l^{3+},}\) the smallest one is \(\mathrm{Al}.\) |
Subtopic: Ionization Energy (IE) |
79%
From NCERT
NEET - 2024
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NEET 2026 - Target Batch - Vital
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NEET 2026 - Target Batch - Vital
Which one of the following represents all isoelectronic species?
1. \(\mathrm{Na^+ , Cl^-, O^- , NO^+}\)
2. \(\mathrm{N_2O, N_2O_4 , NO^+, NO}\)
3. \(\mathrm{Na^+ , Mg^{2+} , O^- , F^-}\)
4. \(\mathrm{Ca^{2+} , Ar, K^+, Cl^-}\)
1. \(\mathrm{Na^+ , Cl^-, O^- , NO^+}\)
2. \(\mathrm{N_2O, N_2O_4 , NO^+, NO}\)
3. \(\mathrm{Na^+ , Mg^{2+} , O^- , F^-}\)
4. \(\mathrm{Ca^{2+} , Ar, K^+, Cl^-}\)
Subtopic: Ionization Energy (IE) |
76%
From NCERT
NEET - 2023
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NEET 2026 - Target Batch - Vital
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NEET 2026 - Target Batch - Vital
The first ionization enthalpies of elements X and Y are 419 kJ mol–1 and 590 kJ mol–1, respectively and the second ionization enthalpies of X and Y are 3069 kJ mol–1 and 1145 kJ mol–1, respectively. The correct statement is:
| 1. | X is an alkali metal and Y is an alkaline earth metal. |
| 2. | X is an alkaline earth metal and Y is an alkali metal. |
| 3. | Both X and Y are alkali metals. |
| 4. | Both X and Y are alkaline earth metals. |
Subtopic: Ionization Energy (IE) |
72%
From NCERT
NEET - 2022
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NEET 2026 - Target Batch - Vital
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NEET 2026 - Target Batch - Vital
The correct order of first ionization enthalpy for the given four element is:
| 1. | C < N < F < O | 2. | C < N < O < F |
| 3. | C < O < N < F | 4. | C < F < N < O |
Subtopic: Ionization Energy (IE) |
78%
From NCERT
NEET - 2022
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NEET 2026 - Target Batch - Vital
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NEET 2026 - Target Batch - Vital
For the second-period elements, the correct increasing order of first ionisation enthalpy is:
| 1. | Li < Be < B < C < O < N < F < Ne |
| 2. | Li < Be < B < C < N < O < F < Ne |
| 3. | Li < B < Be < C < O < N < F < Ne |
| 4. | Li < B < Be < C < N < O < F < Ne |
Subtopic: Ionization Energy (IE) |
77%
From NCERT
NEET - 2019
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NEET 2026 - Target Batch - Vital
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NEET 2026 - Target Batch - Vital
In which of the following options, the order of arrangement does not agree with the variation of the property indicated against it?
| 1. | B < C < N < O (increasing first ionisation enthalpy) |
| 2. | I < Br < F < Cl (increasing negative electron gain enthalpy) |
| 3. | Li < Na < K < Rb (increasing metallic radius) |
| 4. | Al3+ < Mg2+ < Na+ <F– (increasing ionic size) |
Subtopic: Ionization Energy (IE) | Electron Affinity (EA) |
82%
From NCERT
NEET - 2016
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NEET 2026 - Target Batch - Vital
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NEET 2026 - Target Batch - Vital
Amongst the elements with the following electronic configurations, which one of them may have the highest ionisation energy?
1.
2.
3.
4.
Subtopic: Ionization Energy (IE) | Electronic Configuration |
75%
From NCERT
AIPMT - 2009
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NEET 2026 - Target Batch - Vital
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NEET 2026 - Target Batch - Vital
The correct order of decreasing second ionization enthalpy of Ti(22), V(23), Cr (24) and Mn(25) is:
1. Cr > Mn > V > Ti
2. V > Mn > Cr > Ti
3. Mn > Cr > Ti > V
4. Ti > V > Cr > Mn
Subtopic: Ionization Energy (IE) |
61%
From NCERT
AIPMT - 2008
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NEET 2026 - Target Batch - Vital
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NEET 2026 - Target Batch - Vital
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