Confirm that the experimentally observed electronic configuration of K, 1s22s22p63s23p64s1 is energetically more stable than the configuration 1s22s22p63s23p63d1.

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i know that it is energetically more stable for the electron to occupy the 4s orbital than the 3d.. but why?

Retyped and answered above.

The observed electronic configuration of K is 1s22s22p63s23p64s1, which means it has 19 electrons. On the other hand, the configuration 1s22s22p63s23p63d1 has 20 electrons.

The stability of an electron configuration is determined by the principle of filling the electron orbitals in order of increasing energy. According to this principle, electrons fill the lowest energy orbitals first before occupying higher energy orbitals.

In the case of potassium (K), the 4s orbital is actually lower in energy than the 3d orbital. This phenomenon is known as the "Aufbau principle." Due to the Aufbau principle, the electrons in potassium prefer to occupy the lower energy 4s orbital before occupying the higher energy 3d orbital.

The 4s orbital is closer to the nucleus and experiences less shielding from the inner electrons, leading to a stronger attractive force from the nucleus. As a result, the 4s orbital is more stable and energetically favorable for electron occupation compared to the 3d orbital.

Therefore, the experimentally observed electronic configuration of K, 1s22s22p63s23p64s1, is indeed energetically more stable than the configuration 1s22s22p63s23p63d1.

To confirm that the experimentally observed electronic configuration of K, 1s22s22p63s23p64s1, is energetically more stable than the configuration 1s22s22p63s23p63d1, we need to compare the energies of the orbitals involved.

First, let's understand the concept of electron configuration. Electron configuration represents the distribution of electrons in the various atomic orbitals of an atom. Orbitals are regions in space where electrons are likely to be found.

In the first configuration, 1s22s22p63s23p64s1, the electron occupies the 4s orbital. In the second configuration, 1s22s22p63s23p63d1, the electron occupies the 3d orbital.

The energy levels of the subshells (s, p, d) are known as the Aufbau principle, which states that electrons fill orbitals in order of increasing energy. According to this principle, electrons will first fill orbitals of lower energy before occupying higher energy orbitals.

Now, let's compare the energy levels of the 3d and 4s orbitals. Even though the 3d orbital is more closely bound to the nucleus, the energy gap between the 3d and 4s orbitals is relatively small.

The energy levels of the orbitals are affected by two main factors: (1) the distance from the nucleus, and (2) the shielding effect of inner electron shells.

In the case of potassium (K), the 4s orbital is energetically more stable than the 3d orbital due to a combination of these factors:

1. Electron-electron repulsion: The 4s orbital is shielded from the full effect of the nucleus by the 1s22s22p6 core electrons. This shielding reduces the electrostatic attraction between the nucleus and the 4s electron, making it easier to remove.

2. Effective nuclear charge: The effective nuclear charge is the net positive charge experienced by an electron. In the 4s orbital, the effective nuclear charge experienced by the electron is lower than in the 3d orbital. Again, this is due to the shielding effect of inner electron shells.

As a result, the 4s orbital in the K atom has a lower energy compared to the 3d orbital, making it energetically more stable and the preferred location for the electron.

In conclusion, the experimentally observed electronic configuration of K, 1s22s22p63s23p64s1, is indeed energetically more stable than the configuration 1s22s22p63s23p63d1 due to the energy levels and the effects of electron-electron repulsion and effective nuclear charge.