Chemistry (Bonding theory and Lewis formulas, Ionic, Moleculer, Vesper structures)

Valence electrons occupying the

energy-level theory says the the electrons in lower energy levels are held so ___ by their___- that, during chemical recation, they remain__

( )

( ) o ( ) <----Orbital

( )

Valence orbitals

Bonding electrons

Lone pair

Quantum mechanics rules

Octet rule

Atoms that always obey the octet rule when bonding.

Atoms that are exceptions to the octet rule.

Lewis symbol also called

Rules for drawing lewis symbol

Ionic bond

Define electronegativity

The atom with highes electronnegativivty

Atom with lowest electronegativity

electronnegativty range

A generalization is that metals have ________ electronegativety while nonmetals tend to have ___ electronegativety

Types of bonding

• If the electronegativities of each atom are relatively high, then neither atom “wins” the competition

• Instead the pair of bonding electrons s shared between two atoms and a COVALENT bond forms

• Usually occurs between two non-metal atoms (2C)

• The electron sharing may be unequal (CO)

• If the electronegativities of the two atoms are very diffrent, the atom with the higher electronegativitie will “win” and take the bonding electron from the lower electronegativities

• an ___ forms when an electron tansfer occurs

• Occurs between metals and non-metals

• ions arrange themselves in position where the maximum total attraction between positive and ions occur

• If the electronegativities of the colliding atoms are both low, then the atoms share valence electrons in a __ bond.

• The valence electrons are not held strongly by their atoms; so they can move arround

• there will be a large number of positive electrons surrounded by a sea of moving electrons

• this is weak attraction in which the metal atoms are not arranged in any particular arranements, which create that is flexable, malleable, and ductile

Scientis figured out that two non-metal atoms must ___ a pair of elctrons in a ______ bond

Covalent bonds shares one pair of elctrons

Covalent bonds shares Two pairs pair of elctrons

Covalent bonds shares three pairs of elctrons

Diatomic molecules

polyatomic molecules

• Molecular compunds do not have simplest ratio formulas like ionic compounds

• Instead, molecular formulas show the actual number and arrangment of the atoms

• all atomsb strive to fill their valence orbitals with a full octet

• Bonding capacity = max # of single covalent bonds

• in turn, the # of ___ determine an atoms bonding capacity

Coordinate covalent bond

o oo

o C o o F o o

o oo

C-F=H

H ---- C _______ C

/\

H

2 bond pairs and 0 lone pairs

4 bond pairs and 0 lone pairs

3 bond pairs and 0 lone pairs

3 bond pairs and 1 lone pairs

2 bond pairs and 2 lone pairs

1 bond pairs and 3 lone pairs

In a ______, the negative (electron) charge is not distributed symmetrically among the atoms making up the molecule.

In a _______, electron distribution is symetrical

Polar molocules

Non-Polar

If the atoms have the same electronegativivty →they attrect shared electrons equally = ________

For a very large electronegativity diffrence, electrons may be transferred from one atom to another, thus cations and anions may form, and an _____________ will hold the compound together

If the atoms have diffrent electronegativities → the attraction for electrons is unequal = ____________

The ____ the electronegativity diffreence, the _____ the bond

NP

Polar covalent

Ionic

The existence of a polar bond ______ necessarily mean that you have a polar molecule

factors of polarity

in a ________ the bond dipoles will canclel each other out

In a polar molecule, the bond dipoles ______ cancel each other out and will be nonzero molecule dipole, or an overal resilant vetctor

_______ compounds are solube in polar solvents

_______ compunds are soluble in non-polar solvents

____molecular forces = forces attraction and repulsion between molecules

____molecular forces = forces attraction within a molecule

when molecules exert weak attractive forces on each other. Intermolecular forces vary over a mcuh wider range and are considerably weaker than the covalent bonds inside a molecule.

In Van der waals forces experimental evidence: take _______ to boil water that it does to decompose water

In Van der waals forces, intermolecular forces are responisble for what we _______ about molecular substance

_______ forces appear to control the physical behaviour of molecular substances

The atrraction between dipoles is called _____

dipole-dipole are amoung the _______ intermolecular

Dipole-Dipole force exists only in ____ molecules

Fritz london suggested that Van der waals forces was actually two forces

Is due to any electron movement within the molecule

Lond force is between ____ molecules

As the number of electrons in the molecule _______, the boiling point increases

more electrons =

Isoelectronic

if both are Isoelectronic what do you do?

• between mols

• weak

• attration over greater distance

• explains physical changes

• Within mol

• strong

• attraction over smaller distance

• explain chemical changes

a hydrogen nucleus is shared between pairs of electrons on adjacent molecules

For hydrogen bonding to occur, 2 this must be simultaneously true about the molecule structure.

Only three possible structures show hydrogen bonding

H bondingis not really a “bond” like a covalent bond, but rather an attraction _______ molecules