CHEM 115 Electronegativity

Linus Pauling

Defined electronegativity

Electronegativity

The ability of a bonded atom to attract electrons in the chemical bond towards itself

Higher en = ____ electron attraction

Greater

Metals have ____ en

Lower

Nonmetals have ____ en

Higher

Group VIIIA (noble gases) en = ___

0

En _____ as you go up groups

Increases

En ____ as you go left to right over columns

Increases

Most en element

F

Use en to determine bond type

Δen = |en2 - en1|

Δen > / = 2

Ionic bond

Δen = 0

Nonpolar covalent bond

0 < Δen < 2

Polar covalent bond

Atoms with different electronegativity values will share electrons _____

Unequally

Bond dipoles

Indicate with delta notation that a partial charge has arisen

Partial negative charge is applied to the more _____ element

electronegative

Polar bonds

unequal sharing of valence electrons

Bond order

number of pairs of e- that are shared btwn 2 atoms

Resonance structures

1. same skeletal arrangement

2. different arrangement of e- pairs

Formal charge = 

#val e- — (#bonds + total #nonbonding e-)

Structure with the least amount of formal charge separation is _____ stable

more

Structure with negative formal charge on _______ element is more stable

more than one

Structure with two positive/negative formal charges on adjacent atoms is _____

not stable