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
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