Hydrogen atom has only one electron. So, mutual repulsion between electrons is absent. However, in multielectron atoms mutual repulsion between the electrons is significant. How does this affect the energy of an electron in the orbitals of the same principal quantum number in multielectron atoms?
In hydrogen atom, the energy of an electron is determined by the value of $n$ and in multielectron atom, it is determined by $n+l$. Hence, for a given principal quantum, number electrons of $s, p, d$ and $f$-orbitals have different energy (for $s, p, d$ and $f, l=0,1,2$ and 3 respectively).
Match the following species with their corresponding ground state electric configuration.
| Atom / Ion | Electronic configuration | ||
|---|---|---|---|
| A. | Cu | 1. | $$ 1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^{10} $$ |
| B. | Cu$$^{2+}$$ | 2. | $$ 1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^{10} 4s^2 $$ |
| C. | Zn$$^{2+}$$ | 3. | $$ 1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^{10} 4s^1 $$ |
| D. | Cr$$^{3+}$$ | 4. | $$ 1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^{9} $$ |
| 5. | $$ 1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^{3} $$ |
A. $\rightarrow(3)$
B. $\rightarrow(4)$
C. $\rightarrow(1)$
D. $\rightarrow(5)$
A. $\mathrm{Cu}(\mathrm{Z}=29) \quad: \quad 1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^{10} 4 s^1$
B. $\mathrm{Cu}^{2+}(Z=29) \quad: \quad 1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^9$
C. $Z n^{2+}(Z=30) \quad: \quad 1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^{10}$
D. $\mathrm{Cr}^{3+}(\mathrm{Z}=24) \quad: \quad 1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 3 d^3$
Match the quantum numbers with the information provided by these.
| Quantum number | Information provided | ||
|---|---|---|---|
| A. | Principal quantum number | 1. | Orientation of the orbital |
| B. | Azimuthal quantum number | 2. | Energy and size of orbital |
| C. | Magnetic quantum number | 3. | Spin of electron |
| D. | Spin quantum number | 4. | Shape of the orbital |
A. $\rightarrow$ (2)
B. $\rightarrow(4)$
C. $\rightarrow(1)$
D. $\rightarrow$ (3)
A. Principal quantum number is the most important quantum number as it determines the size and to large extent the energy of the orbital.
B. Azimuthal quantum number determines the angular momentum of the electron and defines the three-dimensional shape of the orbital.
C. Magnetic quantum number gives information about the spatial orientation of orbitals with respect to a standard set of coordinate axes.
D. Spin quantum number arises from the spectral evidence that an electron in its motion around the nucleus in an orbit also rotates or spin about its own axis.
Match the following rules with their statements.
| Rules | Statements | ||
|---|---|---|---|
| A. | Hund's Rule | 1. | No two electrons in an atom can have the same set of four quantum numbers. |
| B. | Aufbau Principle | 2. | Half-filled and completely filled orbitals have extra stabilty. |
| C. | Pauli Exclusion Principle | 3. | Pairing of electrons in the orbitals belonging to the same subshell does not take place until each orbital is singly occupied. |
| D. | Heisenberg's Uncertainty Principle | 4. | It is impossible to determine the exact position and exact momentum of a subatomic particle simultaneously. |
| 5. | In the ground state of atoms, orbitals are filled in the order of their increasing energies. |
A. $\rightarrow$ (3)
B. $\rightarrow$ (5)
C. $\rightarrow$ (1)
D. $\rightarrow$ (4)
A. Hund's rule states that pairing of electrons in the orbitals belonging to the same subshell ( $p, d$ or $f$ ) does not take place until each orbital belonging to that subshell has got one electron each i.e., it is singly occupied.
B. Aufbau principle states that in the ground state of the atoms, the orbitals are filled in order of their increasing energies.
C. According to Pauli exclusion principle, no two electrons in an atom can have the same set of four quantum numbers.
D. Heisenberg's uncertainty principle states that it is impossible to determine the exact position and exact momentum of a subatomic particle simultaneously.
Match the following.
| Column I | Column II | ||
|---|---|---|---|
| A. | X-rays | 1. | $$v=10^0-10^4$$ Hz |
| B. | Ultraviolet wave (UV) | 2. | $$v=10^{10}$$ Hz |
| C. | Long radio waves | 3. | $$v=10^{16}$$ Hz |
| D. | Microwave | 4. | $$v=10^{18}$$ Hz |
A. $\rightarrow(4)$
B. $\rightarrow(3)$
C. $\rightarrow$ (1)
D. $\rightarrow(2)$
| Name | Frequency | Uses | |
|---|---|---|---|
| A. | X-rays | $$ 2 \times 10^{16}-3 \times 10^{19} \mathrm{~Hz} $$ |
Medical pictures, material testing |
| B. | Ultraviolet wave (UV) | $$ 7.9 \times 10^{14}-2 \times 10^{16} \mathrm{~Hz} $$ |
Germisidal lamp |
| C. | Long radio waves | $$ 10^0-10^4 \mathrm{~Hz} $$ |
Signal transmission |
| D. | Microwave | $$ 1 \times 10^9-5 \times 10^{11} \mathrm{~Hz} $$ |
Cooking radar |