1. Concept: Types of Chemical Bonds
Chapter 6
Concept: Types of Chemical Bonds

2. What is chemical bonding?
Occurs when there is a strong attraction between the valence electrons of one atom and the nucleus of another atom
Formed by rearranging electrons
Atoms have relatively high potential energy as independent particles; but, tend to move toward low potential energy
The way electrons are distributed will determine the type of bond
Most chemical bonds are partly ionic and partly covalent

3. What is chemical bonding?
3 types of Chemical Bonding
Ionic
Covalent
Metallic
Ionic and covalent are the two main types of bonding!!!!

4. LEQ: What are characteristics of ionic bonding?
Between metal and nonmetal
Electrical attraction (opposite charges hold compounds together).
Smallest particle is an ion
Solid at room temperature; but, brittle
Crystalline lattice structure (repeating patterns of ions)

5. LEQ: What are characteristics of ionic bonding?
Stronger than covalent bonds
Formula unit
Makes atoms more stable
Lowers potential energy
High melting and boiling points
Good conductors of electricity (in molten state)

6. LEQ: What are characteristics of ionic bonding?
Ionic bonds (giving or taking of electrons)
Cations
+ charge
Lose/give up electrons
metals
Anions
(-) charge
Gain electrons
nonmetals

7. LEQ: What are characteristics of ionic bonding?
Terms to know
Ionic compound
Compound composed of +/- ions that combine so that they are equal
Formula Unit
Simplest ratio of (+) ions to (–) ions represented by the formula

8. LEQ: What are characteristics of covalent bonding?
2 nonmetals share electrons so that both have 8 valence electrons (except H)
Forms molecules
Liquid or gas at room temperature
Illustrated with Lewis Dot
Can be polar or non-polar
Not as strong as/weaker than ionic bonds
Makes atoms more stable by lowering potential energy
Low melting and boiling points

9. LEQ: What are characteristics of covalent bonding?
Non-polar covalent
Electrons shared equally
No charge created
Occurs between 2 identical atoms
7 diatomic molecules (HOClBrFIN)

10. LEQ: What are characteristics of covalent bonding?
Polar Covalent
Electrons not shared equally (tug-of-war)
Electrons spend more time around the more electronegative atom
Slight charges created
(-) charge around the more electronegative atom.
Example: water, HCl (hydrochloric acid)

11. LEQ: What are characteristics of covalent bonding?
Terms to Know
Molecule
A neutral group of atoms held together by a covalent bond
Molecular compound
Another name for covalent compound
Chemical formula
# of atoms of each element in a compound represented by using symbols and subscripts

12. LEQ: What are characteristics of covalent bonding?
Terms to Know
Molecular Formula
Types and numbers of atoms in a single molecule
Used for covalent compounds
Example: H2O

13. LEQ: What are characteristics of covalent bonding?
1. To lower potential energy by making the substance more stable
Attract/repel each other until the distance between the atoms is reached where the repulsion between the like charges equal the attraction of the opposite charges
Atoms have relatively high potential energy as independent particles; but, tend to move toward low potential energy

14. LEQ: What are characteristics of covalent bonding?
2. To form octet
Octet rule – atoms tend to form compounds (by gaining, losing, or sharing electrons) so that the highest energy level is full (8 electrons in s & p orbitals)
How many more electrons does nitrogen need to satisfy the octet rule if its electron configuration is 1s22s22p3 ?

15. LEQ: What are characteristics of covalent bonding?
Exceptions to octet rule:
Hydrogen – surrounded up to 2 electrons
Boron – up to 6 electrons
Fluorine, oxygen, and chlorine – more than 8 electrons because they have high electronegativities

16. LEQ: What are characteristics of ionic and covalent bonding?
Differences in Electronegativity
0-0.3 (0%-5%)Non-polar covalent
Diatomic molecules
(5%-50%)polar-covalent
HCl
(50% - 100%)ionic
NaCl

17. Lewis Dot Structures
Uses electron dot to illustrate what a molecule looks like
Electron dot notation
Only shows valence electrons
Symbol of element stands for nucleus and all inner shell electrons
Lewis Dot can show single, double, and triple bonds
If carbon is present, use as central atom. If not, use the least electronegative atom as the central atom. NEVER use hydrogen as central atom.

18. Lewis Dot Structures
Examples:
IBr O2
CH3Br
OF2
HCL
CF4

19. What are unique characteristics of Polyatomic Ions?
A group of covalently bonded atoms that have a charge representing extra electrons
PO43- , NH4+
Negative – excess of electrons
Positive – shortage of electrons
Has molecular and ionic characteristics

20. Metallic Bonding
Chemical bonding that results from an attractions between metal atoms and the surrounding electrons
The ions are capable of sliding past one another
Creates the characteristics of being malleable, ductile, and shiny.