If the position of the electron were measured with an accuracy of +0.002 nm, the uncertainty in the momentum of the electron would be: 

1. 5.637 × 10–23 kg m s–1

2. 4.637 × 10–23 kg m s–1

3. 2.637 × 10–23 kg m s–1

4. 3.637 × 10–23 kg m s–1

Subtopic:  Heisenberg Uncertainty Principle |
 77%
Level 2: 60%+
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The quantum numbers of six electrons are given below. Arrange them in the increasing order of energies:

i. n = 4, l = 2, \(m_l\) = –2 , \(m_s\) = –1/2

ii. n = 3, l = 2, \(m_l\) = 1 , \(m_s\) = +1/2

iii. n = 4, l = 1, \(m_l\) = 0 , \(m_s\) = +1/2

iv. n = 3, l = 2, \(m_l\) = –2 , \(m_s\) = –1/2

v. n = 3, l = 1, \(m_l\) = –1 , \(m_s\) = +1/2

vi. n = 4, l = 1, \(m_l\) = 0 , \(m_s\) = +1/2
 

1. v(3p) < ii(3d) < vi(4p) < i(4d) = iv(3d) < iii(4p)

2. v(3p) < ii(3d) = iv(3d) < iii(4p) = vi(4p) < i(4d)

3. vi(4p) < i(4d) < v(3p) < ii(3d) < iv(3d) < iii(4p)

4. v(3p) < ii(3d) < iv(3d) < iii(4p) < vi(4p) < i(4d)

Subtopic:  AUFBAU Principle |
 77%
Level 2: 60%+
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Which electron in a bromine (Br) atom experiences the lowest effective nuclear charge?
1. 2p and 3p
2. 4p
3. 2p
4. 3p
Subtopic:  Number of Electron, Proton & Neutron |
 74%
Level 2: 60%+
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For each of the following pairs of atomic orbitals, identify the one that experiences a larger effective nuclear charge (\(Z_{\text{eff}}\)):

(i) 2s and 3s, (ii) 4d and 4f, (iii) 3d and 3p.

1. 2s, 4d, 3p

2. 3s, 4f, 3d

3. 3s, 4f, 3p

4. 2s, 4d, 3d

Subtopic:  Pauli's Exclusion Principle & Hund's Rule |
 68%
Level 2: 60%+
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The unpaired electrons in aluminium and silicon occupy 3p orbitals in their ground states. Which of the following experiences a greater effective nuclear charge?

1. Electrons in the 3p orbital of silicon

2. Electrons in the 5d orbital of aluminium

3. Electrons in the 3p orbital of aluminium

4. Both experience the same effective nuclear charge

 

Subtopic:  Number of Electron, Proton & Neutron |
 57%
Level 3: 35%-60%
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Identify the element with the highest number of unpaired electrons in its ground state from the given options :

1. P

2. Fe

3. Kr

4. Cr
Subtopic:  Pauli's Exclusion Principle & Hund's Rule |
 72%
Level 2: 60%+
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The number of electrons that can be present in the subshells having ms value of \(-\frac{1}{2}\) for n = 4 are:

1. 36 2. 4
3. 16 4. 2
Subtopic:  Shell & Subshell |
 76%
Level 2: 60%+
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Which of the following gives the atomic numbers of the elements having outermost electronic configurations 3s¹ and 2p⁵, respectively?

1. 9, 7

2. 9, 11

3. 11, 5 

4. 11, 9

Subtopic:  Shell & Subshell |
 78%
Level 2: 60%+
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The circumference of the Bohr orbit for the H atom is related to the de Broglie wavelength associated with the electron revolving around the orbit by the following relation: 
1. 2πr=nλ
2. πr = 2nλ
3. mvr = nλ
4. vr = 2nλ

Subtopic:  Bohr's Theory | De Broglie Equation |
 83%
Level 1: 80%+
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Which among the following are isoelectronic species?

1. Na+,K+,Ca2+,Mg2+

2. Ca2+,Mg2+,S2-,K+

3. Ca2+,Ar,S2-,K+

4. None of the above

Subtopic:  Number of Electron, Proton & Neutron |
 76%
Level 2: 60%+
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