Q. No.| 1. | Al and B | 2. | Be and Li |
| 3. | Cl and O | 4. | Si and N |
Which of the following triads do not follow Dobereiner's law of triads?
| 1. | Li, Na, K | 2. | Ca, Sr, Ba |
| 3. | Be, Mg, Ca | 4. | Cu, Ag, Au |
The statement that is incorrect for the periodic classification of elements is:
| 1. | The properties of elements are a periodic function of their atomic number. |
| 2. | Non-metallic elements are lesser in number than metallic elements. |
| 3. | The first ionization energies of elements along a period do not vary in a regular manner with an increase in atomic number. |
| 4. | For transition elements, the d-subshells are filled with electrons monotonically with an increase in atomic number. |
| Assertion (A): | The physical and chemical properties of the elements are periodic functions of their atomic numbers. |
| Reason (R): | Periodicity based on the atomic number was illustrated by Mendeleev's periodic law. |
| 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. | Both (A) and (R) are False. |
Among the following, the elements that can show covalency greater than 4 is/are:
(a) Be
(b) P
(c) S
(d) B
Choose the correct option
1. (a), (d)
2. (b), (c)
3. (c), (d)
4. (b), (d)
The properties among the following can be shown by the element belonging
to the 3rd period and group 13 of the periodic table:
(a) Good conductor of electricity
(b) Liquid, metallic
(c) Solid, metallic
(d) Solid, non-metallic
Choose the correct option :
1. (a), (c)
2. (b), (c)
3. (c), (d)
4. (b), (d)
Match the name of elements given in list-I with the corresponding electronic configuration given in list-II and select the correct answer using the codes given below:
|
List-I (element) |
List-II (electronic configuration) |
||
| (a) |
Gallium |
1. |
1s2 2s2 2p6 3s2 3p6 4s2 3d1 |
| (b) |
Vanadium |
2. |
1s2 2s2 2p6 3s2 3p6 4s2 3d10 |
| (c) |
Zinc |
3. |
1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p1 |
| (d) |
Scandium |
4. |
1s2 2s2 2p6 3s2 3p6 4s2 3d3 |
Codes :
| (a) | (b) | (c) | (d) | |
| 1. | 2 | 1 | 3 | 4 |
| 2. | 3 | 4 | 1 | 2 |
| 3. | 3 | 4 | 2 | 1 |
| 4. | 1 | 2 | 4 | 3 |
The number of elements present in the fifth period of the periodic table is:
1. 10
2. 8
3. 32
4. 18
1. 107
2. 118
3. 126
4. 102
1. Curium (Z = 96)
2. Californium (Z = 98)
3. Uranium (Z = 92)
4. Terbium (Z = 65)
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