Chapter 2

Pauli's exclusion principle states that: (a) Nucleus of an atom contains no negative charge (b) Electrons move in circular orbits around the nucleus (c) Electrons occupy orbitals of lowest energy (d) All the four quantum numbers of two electrons in an atom cannot be equal.

Maximum number of electrons in a subshell is given by (a) \((2 l+1)\) (b) \(2(2 l+1)\) (c) \((2 l+1)^{2}\) (d) \(2(2 l+1)^{2}\)

The orbital angular momentum of \(3 p\) electron is : (a) \(\sqrt{3} h\) (b) \(\sqrt{6} h\) (c) zero (d) \(\sqrt{2} \frac{h}{2 \pi}\)

The atomic orbitals are progressively filled in order of increasing energy. The principle is called as: (a) Hund's rule (b) Aufbau principle (c) Exclusion principle (d) de-Broglie rule

The ratio of magnetic moments of Fe (III) and Co (II) is : (a) \(\sqrt{5}: \sqrt{7}\) (b) \(\sqrt{35}: \sqrt{15}\) (c) \(7: 3\) (d) \(\sqrt{24}: \sqrt{15}\)

A compound of vanadium has a magnetic moment \((\mu)\) of \(1.73 \mathrm{BM}\). If the vanadium ion in the compound is present as \(\mathrm{V}^{x+}\), then, the value of \(x\) is? (a) 1 (b) 2 (c) 3 (d) 4

The correct order of screening effects of \(s, p, d, f\) sub-shells is : (a) \(s>p>d>f\) (b) \(sp>s>f\) (d) \(s>f>d>p\)

The e quantum numbers of four electrons (e1 to e4) are given below : $$ \begin{array}{ccccccccc}n & l & m & s & & n & l & m & s \\ 3 & 0 & 0 & +1 / 2 & e 2 & 4 & 0 & 0 & 1 / 2 \\ 3 & 2 & 2 & -1 / 2 & e 4 & 3 & 1 & -1 & 1 / 2\end{array} $$ \(\begin{array}{r}\text { The quar } \\ e 1 & n \\ e 3 & 3\end{array}\) The correct order of decreasing energy of these electrons is: (a) \(e 4>e 3>e 2>e 1\) (b) \(e 2>e 3>e 4>e 1\) (c) \(e 3>e 2>e 4>e 1\) (d) \(e 1>e 4>e 2>e 3\)

The energy of an electron of \(2 p_{y}\) orbital is (a) Greater than \(2 p_{x}\) orbital (b) Less than \(2 p_{s}\) orbital (c) Equal to \(2 \mathrm{~s}\) orbital (d) Same as that of \(2 p_{x}\) and \(2 p_{z}\) orbital

How do the energy gaps between successive electron energy levels in an atom vary from low to high \(n\) values? (a) All energy gaps are the same (b) The energy gap decreases as \(n\) increases (c) The energy gap increases as \(n\) increases (d) The energy gap changes unpredictably as \(n\) increases