Question

electronegativity with best examples

Answer 1

Electronegativity describes the degree to which an atom attracts electrons in a chemical bond. The difference in the electronegativity of two atoms determines their bond type. If the electronegativity difference is more than 1.7, the bond will have an ionic character. If the electronegativity difference is between 0.4 and 1.7, the bond will have a polar covalent character. Lastly, if the electronegativity difference is less than 0.4, the bond will have a nonpolar covalent character.
The Concept of Electronegativity
Unlike many other periodic trends, electronegativity does not have actual units. Instead, it is a way of combining two other periodic trends: ionization energy and electron affinity. Ionization energy is the amount of energy required to remove an electron from a neutral atom. Electron affinity is the amount of energy given off or required when a neutral atom gains an electron. Electronegativity does not have any units. However, the Pauling scale for electronegativity lists cesium as the least electronegative element, with a value of 0.79. In this scale, fluorine is the most electronegative element, with a value of 4.0.
Sodium Chloride, an Ionic Bond
Sodium has an electronegativity of 0.9, while chlorine has an electronegativity of 3.0. The difference between these values is 2.1, which means that sodium chloride has an ionic bond. In an ionic bond, the more electronegative element will attract an electron from the less electronegative element. In this case, chlorine becomes a Cl- ion, while sodium becomes an Na+ ion.
Water, a Polar Bond
Hydrogen has an electronegativity of 2.0, while oxygen has an electronegativity of 3.5. The difference in electronegativities is 1.5, which means that water is a polar covalent molecule. This means that the electrons are drawn significantly towards the more electronegative element, but the atoms do not become ionized. In water, an electron from each of the hydrogen atoms is drawn towards the oxygen atom. In this case, the oxygen atom has a partial negative charge, whereas the hydrogen atoms have partial positive charges.
Hydrogen Gas, a Covalent Bond
In hydrogen gas, two hydrogen atoms bond together. The electronegativity difference between these atoms is zero. This is a nonpolar covalent bond. In this case, the electrons of the two atoms do not favor one atom over the other. Instead, they orbit both nuclei and are said to be shared between the two atoms. Covalent bonds can exist between two different elements as well, as long as their electronegativity difference is less than 0.4.

Answer 2

Electronegativity is a measure of the tendency of an atom to attract a bonding pair of electrons. The Pauling scale is the most commonly used. Fluorine (the most electronegative element) is assigned a value of 4.0, and values range down to cesium and francium which are the least electro negative art 0.7.Hydrogen has an electronegativity of 2.0, while oxygen has anelectronegativity of 3.5. The difference in electronegativities is 1.5, which means that water is a polar covalent molecule. This means that the electrons are drawn significantly towards the more electronegative element, but the atoms do not become ionized.It is no wonder the electron pair gets dragged so far towards the chlorine that ions are formed. Electronegativity increases across aperiod because the number of charges on the nucleus increases. That attracts the bonding pair of electrons more strongly.Electronegativity, symbol χ, is a chemical property that describes the tendency of an atom to attract electrons (or electron density) towards itself. An
atom's electronegativity isaffected by both its atomic number and the distance at which its valence electrons reside from the charged nucleus.In general electronegativity is the measure of an atom's ability to attract electrons to itself in a covalent bond. Because fluorine is the mostelectronegative element, the electrons tend to "hang out" more toward the fluorine atom when fluorine is covalently bonded to other atoms.