elektronnegativitása

Elektronnegativitása refers to the tendency of an atom to attract a bonding pair of electrons. It is a fundamental chemical property that influences how atoms interact with each other in molecules. When two atoms form a covalent bond, the electrons in that bond are not always shared equally. The more electronegative atom will pull the electron pair closer to itself, resulting in a partial negative charge on that atom and a partial positive charge on the less electronegative atom. This unequal sharing of electrons is what creates polar covalent bonds.

The concept of electronegativity was first quantified by Linus Pauling in 1935. He developed a relative scale, known as the Pauling scale, where fluorine is assigned the highest electronegativity value (4.0). Other elements are ranked relative to fluorine. Generally, electronegativity increases across a period from left to right in the periodic table and decreases down a group from top to bottom. Elements on the right side of the periodic table, such as halogens and oxygen, tend to be highly electronegative, while elements on the left side, like alkali metals and alkaline earth metals, are less electronegative.

Electronegativity plays a crucial role in determining the polarity of molecules and predicting the types of chemical reactions that can occur. For instance, the difference in electronegativity between two bonding atoms can indicate whether a bond will be nonpolar covalent, polar covalent, or even ionic. This property is essential for understanding chemical bonding, molecular structure, and reactivity.