1. Chapter 8: Covalent Bonding
Mr. Stripling
Pre-AP Chemistry
Room 402

2. Covalent Bonds
Chemical bond that results from sharing valence electrons
Forms a molecule
Can form between elements that are near each other on the periodic table
Most are between atoms of nonmetallic elements

3. Covalent Bond Formation
Diatomic molecules (H2, O2, F2, Cl2, Br2, and I2) form when two atoms of each element share electrons
One pair of electrons are covalently bonded (shared) and three pairs of electrons are lone pairs (not shared)

4. A chemical bond that results from sharing valence electrons?
Most of these bonds are between atoms of what type of elements?
H2, O2, F2, Cl2, Br2, and I2 are examples of what type of molecules?

5. Single Covalent Bonds When only one pair of electrons is shared
Hydrogen m0lecule
B and C represent Lewis structures

6. Group 17 and Single Bonds The halogens have 7 valence electrons
Form single covalent bonds to form an octet
Example: Fluorine from earlier

7. Group 16 and Single Bonds
Atoms of group 16 can share two electron and form two covalent bonds

8. Group 15 and Single Bonds
Group 15 elements form three covalent bonds with atoms of nonmetals

9. Group 14 and Single Bonds
Atoms of group 14 form four covalent bonds

10. What is a covalent bond formed by one pair of electrons being shared?
Group 16 elements can share how many electrons?
Group 15 elements can form how many covalent bonds?
Which group on the periodic table can form 4 covalent bonds?

11. Sigma Bond
Single covalent bonds, represented by the Greek letter sigma ( )
Occur when orbitals of atoms overlap

12. Multiple Covalent Bonds
Occurs when atoms share multiple pairs of electrons
Double and triple bonds

13. Double Bonds
Occur when two atoms share two pairs electrons

14. Triple Bonds
Forms when three pairs of electrons are shared between two atoms

15. How many pairs of electrons are shared in a double covalent bond?
How many electrons are shared in a triple bond?

16. Strength of Covalent Bonds
Depends on distance between the bonded nuclei
The shorter the bond length, the stronger the bond
Single bonds < triple bonds

17. Bonds and Energy
Energy changes occur when bonds between atoms form or break
Energy is released when a bond forms
Energy must be added to break a bond

18. Team Classwork Problems 1-6 on page 244
Problem 1 (a-d) on page 980 for Chapter 8

19. Naming Binary Molecular Compounds
Made of nonmetal atoms (NOT metal atoms or ions)
Example: dinitrogen monoxide (N2O)
Naming rules:
The first element in the formula is always named first, using the entire element name (nitrogen)
The second element in the formula is named using its root and adding the suffix –ide (oxide)
Prefixes are used to indicate the number of atoms of each element that are present in the compound (dinitrogen monoxide)

20. Exceptions to the rules
The first element in the compound never uses the prefix mono- (CO is carbon monoxide, not monocarbon monoxide)

21. When naming a binary molecular compound, what part is named first?
Which part of the formula is named using its root and adding the suffix –ide?
The first element in the compound never uses which prefix?
Name this binary covalent compound: S9F6

22. Common Names for Molecular Compounds
Water = H2O = dihydrogen monoxide
Ammonia = NH3 = nitrogen trihydride
Nitric oxide = NO = nitrogen monoxide

23. Naming Binary Acids
Binary acids contain hydrogen and one other element
Example: hydrochloric acid (HCl)
First word has the prefix hydro- to name the hydrogen part of the compound
The rest of the first word consists of a form of the root of the second element plus the suffix –ic (HCl becomes hydrochloric)
The second word is always acid

24. Binary acids can contain more that two elements
As long as no oxygen is present in the acidic compound formula it is named as a binary acid
The root of the second part of the name is the root of the polyatomic ion
Example: HCN = hydrocyanic acid

25. Binary acids contain what?
The rest of the first word of a binary acid consists of a form of the root of the second element plus what suffix?
The first word of a binary acid contains what prefix?
When naming a binary acid, what is the second word?
Can binary acids contain more than two elements
If oxygen is present, is it still a binary acid?

26. Naming Oxyacids
Oxyacid – an acid that contains both a hydrogen atom and an oxyanion
Oxyanion – a polyatomic ion containing one or more oxygen atoms

27. Identify the oxyanion present
The first word of an oxyacid’s name consists of the root of the oxyanion and the prefix per- or hypo- if it is part of the oxyanion’s name
If the oxyanions' name ends with the suffix –ate, replace it with the suffix –ic. If the name of the oxyanion ends with the suffix –ite, replace it with –ous
Example: nitric acid (HNO3)
NO3-, the nitrate ion becomes nitric
The second word of the name is always acid

28. What is an acid that contains both a hydrogen atom and an oxyanion?
What is a polyatomic ion containing one or more oxygen atoms?
If the oxyanions' name ends with the suffix –ate, replace it with what suffix?
If the name of the oxyanion ends with the suffix –ite, replace it with what suffix?

29. Team Classwork Problems 14-17 on page 249 Problems 19-23 on page 251