HYPERVALENT MOLECULE Meaning and
Definition
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A hypervalent molecule refers to a chemical compound that contains at least one atom with more than the conventional number of valence electrons. Valence electrons are the outermost electrons in an atom, responsible for its chemical bonding capacity. Typically, atoms are known to possess a certain number of valence electrons, which is determined by their position on the periodic table. For example, carbon has a valence of 4, meaning it can form up to 4 bonds.
However, certain atoms can exceed their normal valence due to unique electron sharing and bonding patterns. Hypervalent molecules often involve central atoms from groups 15-18 of the periodic table (such as phosphorus, sulfur, chlorine, and iodine) in combination with other elements, creating an arrangement that helps accommodate the additional electrons.
The concept of hypervalency challenges the traditional Lewis octet rule, which suggests that atoms tend to form chemical bonds to achieve a stable configuration with eight valence electrons. In hypervalent molecules, this rule can be exceeded, allowing the central atom to share more than the conventional number of electrons with surrounding atoms.
Hypervalent molecules have intrigued chemists due to their unique structure and reactivity. They play a significant role in various chemical reactions and provide insights into the fundamental nature of chemical bonding. Hypervalency also finds applications in fields such as organic chemistry, materials science, and even pharmaceuticals. Understanding and characterizing hypervalent molecules contribute to advancing our knowledge of the chemical world, opening up new possibilities for innovation and discovery.
Etymology of HYPERVALENT MOLECULE
The term "hypervalent molecule" is derived from the combination of two words: "hyper-" and "valent".
1. "Hyper-" comes from the Greek word "hyper", meaning "above" or "beyond". In the context of chemistry, it often refers to something exceeding the normal or usual state.
2. "Valent" is derived from the Latin word "valens", which means "powerful" or "strong". In chemistry, it specifically refers to the combining capacity of an atom, which is determined by its number of valence electrons.
When these two terms are combined, "hypervalent" refers to a molecule that has a higher number of electron pairs around the central atom than would be predicted by the octet rule (the general observation that atoms tend to combine in such a way that they have eight electrons in their valence shell to achieve stability).
