Electron Configuration and Valence Electrons
Ever wonder why some elements explode in water while others barely react at all? It's all about their electron configuration - the way electrons arrange themselves around an atom's nucleus in energy levels or shells.
Each shell contains subshells (labeled s, p, d, and f) that can hold different numbers of electrons. For example, an s subshell holds 2 electrons, while a p subshell holds 6. When writing electron configurations, we show this as a formula like 1s² 2s² 2p⁶ 3s² for magnesium.
The most important electrons are those in the outermost shell, called valence electrons. These are the social butterflies of the atomic world - they can be removed, shared, or transferred to other atoms, making chemical reactions possible.
💡 The octet rule explains why elements react the way they do - atoms want eight valence electrons to be stable (like the noble gases). Elements with fewer than eight electrons are more reactive because they're trying to gain, lose, or share electrons to reach that stable state of eight!