Chemical Bonding

BASED ON LEWIS DOT STRUCTURES

4 TYPES OF BONDING

IONIC BONDING COVALENT BONDING HYDROGEN

BONDING METALLIC BONDING

Examples of Lewis Dot Diagrams

H Electrons in the outer shell He 1 2 Li Be B C N O F Ne 1 2 3 4 5 6 7 8

Group 18 – Noble Gases

All Noble gases have filled outer shells. All Noble gases are HAPPY and stable.

Helium has 2e- in outer shell therefore already Happy.

Other Noble gases have 8 e-’s which fill their outer shells (Octet)

Filled outer shells prevents the Noble gases from reacting with other elements.

All other atoms try to get outer shells like

the Noble Gases have.

Noble Gases -- The Dream Team

A filled outer shell is called an OCTET and is the HEAVEN condition for ions or atoms

All other atoms try to reach the HAPPY condition by doing 1 of 3 options

Things Atoms do to become HAPPY

Ionic Bonding Gain an e- : H• + 1e- •H• (H-1) (2e- in outer shell) 

Lose an e- : H• H+ + 1e- (H+1) (Zero e-’s in outer shell) 

Covalent BondingShare e-’s : (2e- in both

outer shells)

Ionic Bonding One atom loses an e-

and becomes positive(+) One atom gains an e-

and becomes negative(-) Opposite charged

particles attract, bond & neutralize.

Usually a weak bond which can be broken by water.

Free ions in water allow for flow of e-’s (electricity).

Usually form crystal lattice.

Group 1 – Alkali Metals

Alkalies can ONLY LOSE 1e- to become: Li• Li+ + 1e-

If it gains or shares 1e- it would then have 1 or more e-‘s in a shell that wants 8e-‘s. This would not be stable.

This is true for the rest of the Alkali Metals.

Group 2 – Alkaline Earth Metals

The Alkaline Earth elements are most likely to lose 2e’s to reach a filled outer shell.

Mg Mg+2 + 2e- They all become a +2 ion. Be+2, Mg+2, Ca+2 and so on. Gaining or sharing will not reach OCTET.

Group 13 – Boron Family

The Boron Family are most likely to lose 3e’s to reach a filled outer shell. B B+3 + 3e-

Therefore they prefer to be a +3 ion. B+3, Al+3, Ga+3 and so on. Gaining or sharing will not reach OCTET

Covalent Bonding

Covalent bonding is sharing of 2 e-’s between 2 nuclei

No CHARGES are involved Based on the Lewis Dot

Structure outer shell Strongest bonds Shared e-’s add toward the

OCTET completion Electron pair is not always

shared equally leading to a POLAR BOND & Molecule

Group 14 – Carbon Family *Unusual*

The Carbon Family can lose the outer 4e-‘s to become C+4 ions falling to a previously filled outer shell 2 e-’s. C C+4 + 4e-’s

The Carbon Family can gain 4e-‘s to become C-4 and fill the outer shell with 8e-s(OCTET).

C + 4e- C-4 They can share their outer 4e-‘s with other atoms

wanting to share(COVALENT BONDING) and reach OCTET in the shape of a TETRAHEDRON.

Group 15 – Nitrogen Family

The Nitrogen Family can gain 3e-’s to become N-3 ions. N2 + 6e- 2N-3

The Nitrogen Family can share 3e-‘s to reach the OCTET.

 Two e-’s are found between N and each H. Diatomic Nitrogen requires a triple bond

sharing 6 e-’s.

Group 16 – Oxygen Family

The Oxygen Family can gain 2e-‘s to become O-2 ions. O2 + 4e- 2O-2

The Oxygen Family can share 2e-‘s to reach the Octet. 4e- shared is a Double bond.

Group 17 -- Halogens

The Halogens could gain 1e- to become a negative ion.

F2 + 2e- 2 F-1  The other possibility is to

share 1 non-paired electron with another atom.

H• + •F  

Hydrogen Bonding

(attraction)

Oxygen attracts e-’s more than Hydrogen. When H and O are bonded, the electrons are closer to

the Oxygen than the Hydrogen. This causes a partial + near Hydrogen and a partial –

near the Oxygen. This is a polar attraction between water molecule. This polarity causes molecules to attract each

other requiring more energy to pull molecules apart. These attractions cause a higher Melting & Boiling

Points for chemicals that have polarity & Hydrogen.

Hydrogen Bonding in Water

Orderly arrangement of molecules caused by Hydrogen bonding in the solid state of water causes solid to expand and float which is unique.

Metallic Bonding

Most solid metals arrange themselves so that 1 atom constantly contacts 12 +other atoms.

The e-’s become very free in this tight packing and can flow as a river of e-’s down the line.

This is the definition of electricity: the flow of loosely held e-’s through a metal.

High melting temperatures are usually noted.

Naming Chemical

Compounds Ionic Bonding Roman Numeral Non-Ionic Bonding

Ionic (Binary) Chemical

Always between a Metal and a Non-metal Name the as found on the periodic table Change the name of the non-metal to –ide

ending For the formula, use the charges from the

Common Ion Chart or Periodic Table families to determine needed subscripts. The + and – ion charges MUST to cancel to “ZERO”.

Ba+2 + 2Cl- add up to zero then charges disappear

BaCl2 is called Barium Chloride using subscripts

Examples of Ionic Bonding

Na+1 + Cl-1 NaCl (1:1)

Ba+2 + 2NO3-1 Ba(NO3)2 (1:2)

Al+3 + 3I-1 AlI3 (1:3)

2 Al+3 + 3CO3-2 Al2(CO3)3

(2:3)

Roman Numerals

Some metals can have 2 or more common ions

Fe+2, Fe+3, Cu+1, Cu+2, Pb+2, Pb+4

You must indicate which ion is being used by placing a Roman Numeral behind the symbol

Elements that must use Roman Numerals are: Fe, Cu, Pb, Ni, Co, Hg, Cr, Sn

Using Roman Numerals Ions with multiple charges

Fe+2 = Fe II Fe+3 = Fe III

Fe+2 + 2OH-1 Fe(OH)2 Iron II Hydroxide

Fe+3 + 3OH-1 Fe(OH)3 Iron III

Hydroxide

Non-Metallic Compounds

Only used if both elements are Non-metals

Use prefixes to declare number of atoms used Mono = 1(used only for second element) Di = 2, Tri = 3, Tetra = 4, Penta = 5, Hexa =

6, Septa = 7, Octa = 8, Nona = 9, Deca = 10 The “a” is sometimes dropped CO = Carbon Monoxide, CO2 = Carbon Dioxide N2O4 = DiNitrogen TetrOxide P2O5 = DiPhosphorus PentOxide