- 1(current)
Q. No.Given below are two statements: One is labelled as Assertion A and the other is labelled as Reason R
In light of the above statements, choose the most appropriate answer from the options given below:
| Assertion (A): | The first ionization enthalpy of O is lower than that of N and F. |
| Reason (R): | The loss of an electron from O leads to stable half-filled p orbital. |
| 1. | (A) is not correct but (R) is correct. |
| 2. | Both (A) and (R) are correct and (R) is the correct explanation of (A). |
| 3. | Both (A) and (R) are correct and (R) is NOT the correct explanation of (A). |
| 4. | (A) is correct but (R) is not correct. |
Subtopic: Ionization Energy (IE) |
61%
Level 2: 60%+
NEET - 2026
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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 |
Level 3: 35%-60%
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) |
74%
Level 2: 60%+
NEET - 2024
Hints
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. | \(\mathrm{Ca^{2+} , Ar, K^+, Cl^-}\) |
Subtopic: Ionization Energy (IE) |
77%
Level 2: 60%+
NEET - 2023
Hints
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%
Level 2: 60%+
NEET - 2022
Hints
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%
Level 2: 60%+
NEET - 2022
Hints
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) |
78%
Level 2: 60%+
NEET - 2019
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