Chapter 2

When an electron jumps from \(\mathrm{L}\) to \(\mathrm{K}\) shell - (a) Energy is absorbed (b) Energy is released (c) Energy is neither absorbed nor released (d) Energy is sometimes absorbed and some times released

The number of unpaired valence electrons in an atom of phosphorus is : (a) 0 (b) 2 (c) 3 (d) 4

Which quantum number defines the orientation of orbital in the space around the nucleus? (a) Principal quantum number \((n)\) (b) Angular momentum quantum number (c) Magnetic quantum number \(\left(m_{l}\right)\) (d) Spin quantum number \(\left(m_{s}\right)\)

What is the maximum number of electrons in an atom that can have the quantum numbers \(n=3\) and \(l=2 ?\) (a) 2 (b) 5 (c) 6 (d) 10

Which of the following statements about an electron with \(m_{l}=+2\) is incorrect? (a) The electron could be in the third shell (b) The electron is in a non-spherical orbital (c) The electron may have \(m_{s}=\frac{1}{2}\) (d) The electron is not in a \(d\) -orbital

In a \(3 d\) subshell, all the five orbitals are degenerate. What does it mean? (a) All the orbitals have the same orientation. (b) All the orbitals have the same shape. (c) All the orbitals have the same energy. (d) All the orbitals are unoccupied.

Which of the following subshell can accomimodate as many. as 10 electrons? (a) \(2 d\) (b) \(3 d\) (c) \(3 d_{x \gamma}\) (d) \(3 d_{-2}\)

Which of the following statements is correct for an electron having azimuthal quantum number \(l=2 ?\) (a) The electron may be in the lowest energy shell. (b) The electron is in a spherical orbital. (c) The electron must have spin \(m_{s}=+\frac{1}{2}\) (d) The electron may have a magnetic quantum number \(=-1\)

For \(4 p_{y}\) orbital: There are nodal plane \(=\ldots\) and azimuthal quantum number \(l=\) (a) 1,0 (b) 0,1 (c) 1,1 (d) 2,1

"No two electrons in an atom can have the same set of four quantum numbers". This principle was enunciated by (a) Heisenberg (b) Pauli (c) Maxwell (d) De-Broglie