Q. No.The element having electronic configuration [Kr]4d104f14, 5s25p6, 6s2 belongs to:
1. s-block
2. p-block
3. d-block
4. f-block
The electronegativity of the following elements increases in the order:
1. C, N, Si, P
2. N, Si, C, P
3. Si, P, C, N
4. P, Si, N, C
The order of screening effect of electrons of s, p, d and f orbitals of a given shell of an atom on electrons in its outer shell is :
1. s > p > d > f
2. f > d > p > s
3. p < d < f < s
4. f > p > s > d
The elements in which electrons are progressively filled in 4f-orbitals are called:
| 1. | Actinoids | 2. | Transition elements |
| 3. | Lanthanoids | 4. | Halogens |
Match the elements given in List-I with the atomic radius given in List-II the correct atomic radius with the corresponding element.
|
List-I
Element
|
List-II
Atomic radius (pm)
|
||
| A. | Be | i. | 74 |
| B. | C | ii. | 85 |
| C. | O | iii. | 112 |
| D. | B | iv. | 77 |
| E. | N | v. | 66 |
| Options: | A | B | C | D | E |
| 1. | i | ii | iii | iv | v |
| 2. | iii | iv | v | ii | i |
| 3. | iv | ii | iii | i | v |
| 4. | v | ii | i | iii | iv |
Column I lists the electronic configurations of certain elements, while Column II provides their electron gain enthalpy values. Match each electronic configuration with the appropriate electron gain enthalpy:
| Column-I (Electron configuration) |
Column-II (Electron gain enthalpy/ kJ mol¯1) |
||
| A. | \(1 s^2 2 s^2 2 p^6\) | (i) | \(-53\) |
| B. | \(1 s^2 2 s^2 2 p^6 3 s^1\) | (ii) | \(-328\) |
| C. | \(1 s^2 2 s^2 2 p^5 \) | (iii) | \(-141\) |
| D. | \( 1 s^2 2 s^2 2 p^4 \) | (iv) | \(+48\) |
| Options: | A | B | C | D |
| 1. | (iv) | (i) | (ii) | (iii) |
| 2. | (i) | (ii) | (iii) | (iv) |
| 3. | (i) | (iv) | (iii) | (ii) |
| 4. | (iv) | (i) | (iii) | (ii) |
| Assertion (A): | Generally, ionisation enthalpy increases from left to right in a period. |
| Reason (R): | When successive electrons are added to the orbitals in the same principal quantum level, the shielding effect of inner core of electrons does not increase very much to compensate for the increased attraction of the electron to the nucleus. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | (A) is false but (R) is true. |
The incorrect order of electronegativity is :
| 1. | Cl > S > P > Si | 2. | Si > Al > Mg > Na |
| 3. | F > Cl > Br > I | 4. | None of the above. |
If an atom has electronic configuration 1s22s22p63s23p63d34s2, we will place it in group number:
| 1. | Fifth | 2. | Fifteenth |
| 3. | Second | 4. | Third |
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 |
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