Chemistry - Electronegativity

Electronegativity

A quantitative measure of the “electron attracting ability” of the atoms present in a molecule

the stronger the pull on the pair of shared electrons toward itself

The bigger the number

Fluorine

The element assigned the highest electronegativity value of 4.0

Fluorine

An element with high ionization energy and high electron affinity

Cesium and Francium

Elements with the smallest electronegativity values

Increases

The general trend of electronegativity across a period from left (metals) to right (nonmetals)

Decreases

The general trend of electronegativity down a group or family in the periodic table

Ionic bond

The type of bond formed between two atoms with a very large difference in electronegativity

Slightly polar covalent bond

The type of bond formed between two atoms with slightly different electronegativities

Covalent bond

The type of bond formed between two atoms with the same electronegativity

Polarity of the bond

The bond characteristic that increases as the difference in electronegativity between two atoms increases

1.7

The approximate difference in electronegativity values above which a bond is considered ionic

Comparing the electronegativities of the two elements

A method to predict whether a bond will be ionic or covalent

Sodium and Chlorine (Na and Cl)

An example of two elements expected to form an ionic bond

Hydrogen and Chlorine (H and Cl)

An example of two elements expected to form a slightly polar covalent bond