The elements in which electrons are progressively filled in 4f-orbitals are called:
1. | Actinoids | 2. | Transition elements |
3. | Lanthanoids | 4. | Halogens |
The correct order of size of the given species is:
1. | I > I– > I+ | 2. | I+ > I– > I |
3. | I > I+ > I– | 4. | I– > I > I+ |
The formation of oxide ion O2-(g), from oxygen atom, requires first an exothermic and then an endothermic step as shown below
Thus, the process of formation of O2- in the gas phase is unfavourable even though O2- is isoelectronic with neon. It is due to the fact that:
1. | Oxygen is more electronegative |
2. | Addition of electron in oxygen results in a larger size of the ion |
3. | Electron repulsion outweighs the stability gained by achieving noble gas configuration |
4. | O- ion has comparatively smaller size than oxygen atom |
The outermost electronic configuration of the last element of the p-block in the 6th period is represented by:
1.
2.
3.
4.
The elements with atomic numbers 35, 53, and 85 are:
1. | Noble gases | 2. | Halogens |
3. | Heavy metals | 4. | Light metals |
Electronic configuration of four elements A, B, C and D are given below :
A.
B.
C.
D.
The correct order of increasing tendency to gain electron is :
1. | A < C < B < D | 2. | A < B < C < D |
3. | D < B < C < A | 4. | D < A < B < C |
Match the correct atomic radius with the corresponding element.
Element |
Atomic radius (pm) |
||
A. |
Be |
i. |
74 |
B. |
C |
ii. |
85 |
C. |
O |
iii. |
112 |
D. |
B |
iv. |
77 |
E. |
N |
v. |
66 |
Codes :
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 |
Match the correct ionization enthalpies and electron gain enthalpies of the following elements.
Elements |
|
|
|
||
(i) |
Most reactive non-metal |
A. |
419 |
3051 |
-48 |
(ii) |
Most reactive metal |
B. |
1681 |
3374 |
-328 |
(iii) |
Least reactive element |
C. |
738 |
1451 |
-40 |
(iv) |
Metal forming binary halide |
D. |
2372 |
5251 |
+48 |
Codes
A | B | C | D | |
1. | ii | i | iv | iii |
2. | i | ii | iii | iv |
3. | i | iv | iii | ii |
4. | iv | i | iii | ii |
Electronic configuration of some elements is given in Column I and their electron gain enthalpies are given in Column II. Match the electronic configuration with electron gain enthalpy.
Column I (Electron configuration) |
Column II (Electron gain enthalpy/kJ mol–1) |
||
A. | 1. |
–53 |
|
B. | 2. |
–328 |
|
C. | 3. |
–141 |
|
D. | 4. |
+48 |
Codes:
Options: | A | B | C | D |
1. | 4 | 1 | 2 | 3 |
2. | 1 | 2 | 3 | 5 |
3. | 1 | 4 | 3 | 2 |
4. | 4 | 1 | 3 | 2 |