Question

Generalize the rules for writing electronic configuration of the first eighteen elements found in the modern periodic table.

Answer 1

The rule for writing electronic configuration of the first eighteen elements found in the modern periodic table:-

1. Electronic configuration means the distribution of electrons in an atom so that their chemical behavior and reactivity can be understood and they can be classified.
2. The filling of the electrons for writing the electronic configuration of the elements is done according to the Aufbau rule, Pauli exclusion principle, and Hund's rule.
3. Aufbau rule states that the order of filling various subshells by means of increasing the order of energy levels using the (n + l) rule. The order of the filling of the orbitals is as follows according to the Aufbau rule $1\mathrm{s},2\mathrm{s},2\mathrm{p},3\mathrm{s},3\mathrm{p},4\mathrm{s},3\mathrm{d},4\mathrm{p},5\mathrm{s},4\mathrm{d},5\mathrm{p},4\mathrm{f},5\mathrm{d},6\mathrm{p},7\mathrm{s}$
4. Every shell has a value assigned to it, which is essentially the Principal Quantum number, or "n." Accordingly, the names of the shells are K, L, M, N for the first shell, n$=1$, n$=2$, n$=3$, and so on.
5. Each subshell has a value known as the Azimuthal Quantum number, or "l," and the number of subshells in a shell is equal to the value of its principal quantum number.
6. For the first shell, for instance, n$=1$, meaning that there is just one potential subshell and that the value for "l" is zero and for $\mathrm{n}=2$, there are two subshells, and the values for "l" are $0$ and$1$, respectively.
7. We have a symbol, such as s p d f, for each value of the subshell.
8. A maximum of two electrons can fit into each orbital. As a result, $1\mathrm{s}$ can hold two electrons, $2\mathrm{s}$ can hold two electrons, $2\mathrm{p}$ can hold six electrons (three orbitals at two electrons each $=$six electrons), and so on.
9. The key components of the Pauli exclusion principle are only two electrons can occupy distinct quantum states in a given orbital and the two electrons present in a given quantum state must be antiparallel to one another and have the opposite spin.
10. According to Hund's rule, every orbital in the sub-level is singly occupied before any orbital is double occupied. and all electrons in a single occupied orbital have the same spin in order to maximize overall spin.