Covalent Bonds How to Draw Dot Structures for Covalent Bonds

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 --Atoms share VEs to achieve an Octet. --Circle Test for an Octet --Hydrogen only needs two electrons --Carbon is always the central atom (never hydrogen) --Least electronegative atom goes in the center. --Valence electrons to start = finish. --Look for Symmetry in the drawing. --Single Bonds --Double Bonds --Triple Bonds --Resonant Structures – Coordinate Bonds

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 H Hydrogen has 1ve

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 H Hydrogen has 1ve Chlorine has 7ves Cl

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 H Hydrogen has 1ve Chlorine has 7ves Cl

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 H Hydrogen has 1ve Chlorine has 7ves Cl They share their valence electrons

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 H Hydrogen has 1ve Chlorine has 7ves Cl They share their valence electrons

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 H Hydrogen has 1ve Chlorine has 7ves Cl They share their valence electrons Circle Test for Octet

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 H Hydrogen has 1ve Chlorine has 7ves Cl They share their valence electrons Circle Test for Octet Eight Electrons!

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 H Hydrogen has 1ve Chlorine has 7ves Cl They share their valence electrons Circle Test for Octet Eight Electrons!

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 H Lewis Diagram for HCl Cl

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 H Those two shared electrons represent a single bond and can be written as: Cl H

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 H Those two shared electrons represent a single bond and can be written as: Cl H The dash represents two electrons in a single bond.

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 H Hydrogen has 1ve H

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 H Hydrogen has 1ve H O Oxygen has 6ves

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 H Hydrogen has 1ve H O Oxygen has 6ves They Share their valence electrons

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 H Hydrogen has 1ve H O Oxygen has 6ves They Share their valence electrons Octet Test!

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 HH O The dashes represents two electrons in a single bond.

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 HH O The dashes represents two electrons in a single bond. Hydrogen is never the central atom!!!

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Chlorine has 7ves Cl

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Chlorine has 7ves Cl Chlorine is Diatomic

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Chlorine has 7ves Cl Chlorine is Diatomic Chlorine shares its valence electrons

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Chlorine has 7ves Cl Chlorine is Diatomic Chlorine shares its valence electrons Octet Test!

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Chlorine has 7ves Cl Chlorine is Diatomic Chlorine shares its valence electrons Octet Test!

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Chlorine has 7ves Cl Chlorine is Diatomic Chlorine shares its valence electrons Octet Test!

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Cl The dash represents two electrons in a single bond.

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Cl The dash represents two electrons in a single bond. All the Halogens behave like this!!!!

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 F F The dash represents two electrons in a single bond. All the Halogens behave like this!!!!

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 F F This is why the Halogens are Diatomic! All the Halogens behave like this!!!!

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 I I This is why the Halogens are Diatomic! All the Halogens behave like this!!!!

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Br Bromine is a dark Red Liquid! All the Halogens behave like this!!!!

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 N Nitrogen has 5ves

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 N Nitrogen has 5ves HH H Hydrogen has 1ve

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 N Nitrogen has 5ves HH H Hydrogen has 1ve Hydrogen and Nitrogen share their valence electrons

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 N Nitrogen has 5ves HH H Hydrogen has 1ve Hydrogen and Nitrogen share their valence electrons Octet Test!

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 N HH H The dashes represents two electrons in a single bond.

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Carbon has 4ves

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Carbon has 4ves C

F F Covalent Bonds C Carbon has 4ves Fluorine has 7ves FF HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2

F F Covalent Bonds C Carbon has 4ves Fluorine has 7ves FF HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2

F F Covalent Bonds C Carbon has 4ves Fluorine has 7ves FF Octet Test! HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2

F F Covalent Bonds C Carbon has 4ves Fluorine has 7ves FF Octet Test! HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2

F F Covalent Bonds C Carbon has 4ves Fluorine has 7ves FF Octet Test! HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2

F F Covalent Bonds C Carbon has 4ves Fluorine has 7ves FF Octet Test! HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2

F F Covalent Bonds C Carbon has 4ves Fluorine has 7ves FF Octet Test! HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2

F F Covalent Bonds C FF HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2

Assignment: H 2 CCl 4 CH 4 NF 3 H 2 S The Next three bonds listed involve double and triple bonds and will be covered in the next video. Draw Covalent Lewis Dot Structures for the molecules on the left.

OO Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Oxygen Has 6ves

OO Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Oxygen Has 6ves Octet Test???

OO Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Oxygen Has 6ves Octet Test???

OO Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Oxygen Has 6ves Octet Test??? Only 7 electrons not 8!

OO Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Oxygen Has 6ves Octet Test??? Only 7 electrons not 8!

O Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 We have to use a DOUBLE BOND O

O Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 We have to use a DOUBLE BOND O

O Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 We have to use a DOUBLE BOND O Octet Test

O Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 We have to use a DOUBLE BOND O Octet Test

O Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 We have to use a DOUBLE BOND O Octet Test

O Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 We have to use a DOUBLE BOND O Each dash represents a bond of two shared electrons.

O Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 We have to use a DOUBLE BOND O We usually pair off the unbonded electrons.

O Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 O Oxygen has 6 valence electrons.

O Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 O Oxygen has 6 valence electrons.

O Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 O Oxygen has 6 valence electrons. Carbon has 4 C

O Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 O Joining them in a single bond fails the octet test for all three atoms. C

O Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 O Joining them in a single bond fails the octet test for all three atoms. C So we have to use a double bond.

O Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 O C So we have to use a double bond.

O Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 O C They Join and All Atoms pass the Octet Test.

O Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 O C They Join and All Atoms pass the Octet Test.

O Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 O C They Join and All Atoms pass the Octet Test.

O Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 O C We Represent these two double bonds like this.

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Nitrogen has 5 Ves. N N

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 A Single Bond Fails the Octet test. N N

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 What about a Double Bond? N N

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 A Double Bond Fails the Octet Test N N

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Nitrogen Requires a Triple Bond! N N

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Nitrogen Requires a Triple Bond! NN

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 This Passes the Octet Test! NN

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 This Passes the Octet Test! NN

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 A Triple Bond! Each Dash represents 2 electrons NN

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Another Way to do this: 1)Each Nitrogen has 5 Ves for 10 electrons total 2)Start with a Single Bond representing 2 electrons Another Way to do this: 1)Each Nitrogen has 5 Ves for 10 electrons total 2)Start with a Single Bond representing 2 electrons NN

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Another Way to do this: 1)Each Nitrogen has 5 VEs for 10 electrons total 2)Start with a Single Bond representing 2 electrons 3)Fill in the next 8 electrons … Another Way to do this: 1)Each Nitrogen has 5 VEs for 10 electrons total 2)Start with a Single Bond representing 2 electrons 3)Fill in the next 8 electrons … NN

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Another Way to do this: 1)Each Nitrogen has 5 VEs for 10 electrons total 2)Start with a Single Bond representing 2 electrons 3)Fill in the next 8 electrons … 4)Move Electrons into bonds until you have an octet. Another Way to do this: 1)Each Nitrogen has 5 VEs for 10 electrons total 2)Start with a Single Bond representing 2 electrons 3)Fill in the next 8 electrons … 4)Move Electrons into bonds until you have an octet. NN

Covalent Bonds HCl H 2 0 Cl 2 NH 3 CF 4 O 2 CO 2 N 2 Another Way to do this: 1)Each Nitrogen has 5 Ves for 10 electrons total 2)Start with a Single Bond representing 2 electrons 3)Fill in the next 8 electrons … 4)Move Electrons into bonds until you have an octet. Another Way to do this: 1)Each Nitrogen has 5 Ves for 10 electrons total 2)Start with a Single Bond representing 2 electrons 3)Fill in the next 8 electrons … 4)Move Electrons into bonds until you have an octet. NN

Bond Strength Think of each bond (dash) as a rubber band holding the atoms together. Two rubber bands is stronger than one but three is stronger than two. Nitrogen (N 2 ) makes up 78% of our atmosphere and is a really stable and inert molecule Think of each bond (dash) as a rubber band holding the atoms together. Two rubber bands is stronger than one but three is stronger than two. Nitrogen (N 2 ) makes up 78% of our atmosphere and is a really stable and inert molecule NN OO F F Weakest Strongest

[NO 3 ] - Nitrate Ion Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the next 8 electrons … 4)Move Electrons into bonds until you have an octet. Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the next 8 electrons … 4)Move Electrons into bonds until you have an octet. [NO 3 ] -

[NO 3 ] - Nitrate Ion Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the next 8 electrons … 4)Move Electrons into bonds until you have an octet. Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the next 8 electrons … 4)Move Electrons into bonds until you have an octet. [NO 3 ] - 5VEs 18VEs 1VE 24VEs

[NO 3 ] - Nitrate Ion Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet. Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet. [NO 3 ] - 5VEs 18VEs 1VE 24VEs N O O O

[NO 3 ] - Nitrate Ion Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet. Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet. [NO 3 ] - 5VEs 18VEs 1VE 24VEs N O O O 18VEs Remaining

[NO 3 ] - Nitrate Ion Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet. Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet. [NO 3 ] - 5VEs 18VEs 1VE 24VEs N O O O 0VEs Remaining

[NO 3 ] - Nitrate Ion [NO 3 ] - 5VEs 18VEs 1VE 24VEs N O O O 18VEs Remaining 0VEs Remaining Oxygen Obeys the Octet! Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet. Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet.

[NO 3 ] - Nitrate Ion [NO 3 ] - 5VEs 18VEs 1VE 24VEs N O O O 18VEs Remaining 0VEs Remaining Oxygen Obeys the Octet! But Nitrogen Does not! Oxygen Obeys the Octet! But Nitrogen Does not! Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet. Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet.

[NO 3 ] - Nitrate Ion Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet. Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet. [NO 3 ] - 5VEs 18VEs 1VE 24VEs N O O O 18VEs Remaining 0VEs Remaining Oxygen Obeys the Octet! But Nitrogen Does not! Oxygen Obeys the Octet! But Nitrogen Does not! Move a Pair from any Oxygen atom and make one double bond!

[NO 3 ] - Nitrate Ion [NO 3 ] - 5VEs 18VEs 1VE 24VEs N O O O 18VEs Remaining 0VEs Remaining Oxygen Obeys the Octet! But Nitrogen Does not! Oxygen Obeys the Octet! But Nitrogen Does not! Move a Pair from any Oxygen atom and make one double bond! Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet. Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet.

[NO 3 ] - Nitrate Ion [NO 3 ] - 5VEs 18VEs 1VE 24VEs N O O O 18VEs Remaining 0VEs Remaining Oxygen Obeys the Octet! But Nitrogen Does not! Oxygen Obeys the Octet! But Nitrogen Does not! Move a Pair from any Oxygen atom and make one double bond! Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet. Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet.

[NO 3 ] - Nitrate Ion [NO 3 ] - 5VEs 18VEs 1VE 24VEs N O O O 18VEs Remaining 0VEs Remaining Oxygen Obeys the Octet! But Nitrogen Does not! Oxygen Obeys the Octet! But Nitrogen Does not! Move a Pair from any Oxygen atom and make one double bond! Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet. Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet.

[NO 3 ] - Nitrate Ion [NO 3 ] - 5VEs 18VEs 1VE 24VEs N O O O 18VEs Remaining 0VEs Remaining Oxygen Obeys the Octet! But Nitrogen Does not! Oxygen Obeys the Octet! But Nitrogen Does not! Move a Pair from any Oxygen atom and make one double bond! Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet. Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet.

[NO 3 ] - Nitrate Ion [NO 3 ] - 5VEs 18VEs 1VE 24VEs N O O O 18VEs Remaining 0VEs Remaining Oxygen Obeys the Octet! Nitrogen has an Octet! Oxygen Obeys the Octet! Nitrogen has an Octet! Move a Pair from any Oxygen atom and make one double bond! Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet. Another Way to do this: 1)Count the total number of VEs 2)Start with a Single Bond representing 2 electrons 3)Fill in the rest of the electrons… 4)Move Electrons into bonds until you have an octet.

Assignment: O 3 C 2 H 6 C 2 H 4 CO C 2 H 2 [OH] - [NH 4 ] + Carbon is always the central atom. Carbon will bond to itself. Least electronegative atom in the middle (never H). Some molecules can have a single and double bond. All of these obey the octet rule. Another Way to do this: 1)Count the Number of VEs 2)Start with a Single Bond representing 2 electrons. 3)Fill in the rest of the electrons making octets where possible… 4)Move Electrons into bonds until you have an octet. Another Way to do this: 1)Count the Number of VEs 2)Start with a Single Bond representing 2 electrons. 3)Fill in the rest of the electrons making octets where possible… 4)Move Electrons into bonds until you have an octet.