Valence Electrons | Core Electrons |
|---|---|
Valence Electrons are farthest away from the nucleus at the outermost shell. This increase in the distance from the nucleus weakens the attractive nuclear interactions raising its energies. | The core electrons are the those present closer to the nucleus. Their attractive interactions with the nucleus are stronger, which lowers their energy and contributes to stability. |
Weakened nuclear attraction makes it less nucleus bound and more likely to loosen and participate in bonding reactions. | Core electrons are bound tightly to the nucleus and are stable. Therefore, they do not participate in any bonding reactions. |
Due to their participation in chemical reactions, valence electrons affect the chemical properties.
The atoms with the same number of valence electrons show similar chemical properties and are grouped together. | Core electrons do not influence the chemical properties of an atom. The core electrons collectively have the electronic configuration of stable inert gas. |
Example- The total number of electrons in a Sodium atom is 11, distributed in different energy levels- 1s2, 2s2, 2p6, 3s1. The 1s, 2s, and 2p are closer to the nucleus than the 3s. The 3 is the outermost shell containing the valence electrons. | Example- The number of core electrons of Sodium is 10 consisting of inner energy levels 1s, 2s, and 2p.
The core electronic configuration of 10 is of stable inert gas Neon. |
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