1. | 158.7 Å | 2. | 158.7 pm |
3. | 15.87 pm | 4. | 1.587 pm |
Which one of the following electrons in the ground state will have least amount of energy?
1. | An electron in hydrogen atom. |
2. | An electron in 2p orbital of carbon atom. |
3. | The electron of copper atom present in 4s orbital. |
4. | The outermost electron in sodium atom. |
A monochromatic infrared range finder of power 1milli watt emits photons with wavelength 1000 nm in 0.1 second. The number of photons emitted in 0.1 second is:
(Given: h = \(6.626 \times 10^{-34} J~s\) , c = \(3 \times 10^8 m~s^{-1}, \) Avogadro number = \(6.022 \times 10^{23}\))
1. \(30 \times 10^{37}\)
2. \(5 \times 10^{14} \)
3. \(30 \times 10^{34} \)
4. \(5 \times 10^{11} \)
Assertion (A): | Half-filled and fully-filled degenerate orbitals are more stable. |
Reason (R): | Extra stability is due to the symmetrical distribution of electrons and high exchange energy. |
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. |
Assertion (A): | \(ns^2\). | Helium and berylium having the similar outer electronic configuration of type
Reason (R): | Both are chemically inert. |
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. |
(i). | n (principal quantum number) can have values 1, 2, 3, 4, ....... |
(ii). | The number of orbitals for a given value of l is (2l+1). |
(iii). | The value of spin quantum numbers is always \(\pm\frac12\). |
(iv). | For l=5, the total number of orbitals is 9. |
List-I (quantum number) |
List-II (Orbital) |
||
(A) | n = 2, \(\ell\) = 1 | (I) | 2s |
(B) | n = 3, \(\ell\) = 2 | (II) | 3s |
(C) | n = 3, \(\ell\) = 0 | (III) | 2p |
(D) | n = 2, \(\ell\) = 0 | (IV) | 3d |
(A) | (B) | (C) | (D) | |
1. | (III) | (IV) | (I) | (II) |
2. | (IV) | (III) | (I) | (II) |
3. | (IV) | (III) | (II) | (I) |
4. | (III) | (IV) | (II) | (I) |