PART II

Covalent Bonds

Ionic Bond = Metal – Non Metal Covalent Bond = Non-Non

= METALS = NONMETALS

So what are covalent bonds?

In covalent bonding, atoms still want to achieve a noble gas configuration (the octet rule).

In covalent bonding, atoms still want to achieve a noble gas configuration (the octet rule). But rather than losing or gaining electrons, atoms now share an electron pair.

Covalent Bonds = elements that share electrons to get octet

In covalent bonding, atoms still want to achieve a noble gas configuration (the octet rule). But rather than losing or gaining electrons, atoms now share an electron pair. The shared electron pair is called a bonding pair

HDrawing Lewis dot structures for covalent compounds 3 STEPS

Cl 2 Chlorine forms a covalent bond with itself

Steps to Solving Lewis Dot Structures 1) Calculate # of Valence Electrons you have to play with (this serves as self-check for late)

Step 1 Cl 2

Steps to Solving Lewis Dot Structures 2) Assign EACH element(s) with appropriate # Ve- (give each side of the symbol 1 electron before you give another)

Step 2 Cl

Steps to Solving Lewis Dot Structures 3) Have elements share Ve- to make each element obey octet rule Each PAIR of electrons shared is a bond, represented by a dash (can have multiple dashes)

Cl How will two chlorine atoms react?

Cl Each chlorine atom wants to gain one electron to achieve an octet

Cl Neither atom will give up an electron (High Ionization Energy)

Cl

octet

Cl circle the electrons for each atom that completes their octets octet

Cl circle the electrons for each atom that completes their octets The octet is achieved by each atom sharing the electron pair in the middle Step 3

Cl circle the electrons for each atom that completes their octets The octet is achieved by each atom sharing the electron pair in the middle

Cl circle the electrons for each atom that completes their octets This is the bonding pair

Cl circle the electrons for each atom that completes their octets It is a single bonding pair

Cl circle the electrons for each atom that completes their octets It is called a SINGLE BOND Copy Down

Cl circle the electrons for each atom that completes their octets Single bonds are abbreviated with a dash Copy Down

Cl circle the electrons for each atom that completes their octets This is the chlorine molecule, Cl 2 Copy Down

O2O2 Oxygen is also one of the diatomic molecules Copy Down

Step 1

Step 2

How will two oxygen atoms bond? OO

OO Each atom has two unpaired electrons

OO

OO

OO

OO

OO

OO

Oxygen atoms are highly electronegative. So both atoms want to gain two electrons. OO

Oxygen atoms are highly electronegative. So both atoms want to gain two electrons. OO

OO

OO

OO

OO

O O Both electron pairs are shared.

6 valence electrons plus 2 shared electrons = full octet O O

6 valence electrons plus 2 shared electrons = full octet O O

two bonding pairs, O O making a double bond Copy Down

O O = For convenience, the double bond can be shown as two dashes. O O Step 3

O O = This is the oxygen molecule, O 2 this is so cool! !

CO 2 Copy Down

Step 1

Step 2

Step 3

CH 4

Step 1

Step 2

Step 3

Ionic Bond = Metal – Non Metal Covalent Bond = non - non