1. The Structure of matter
Physical Science - Chapter 5
Jones

2. What will we be learning?
Section 1: Compounds and Molecules
Distinguish between compounds and mixtures (review from Ch 2!).
Relate the chemical formula of a compound to the relative numbers of atoms or ions present in the compound (ALSO review from Ch 2!).
Describe how the chemical structure of a compound affects its properties.

3. “Compound” What does this word mean?
Something that involves more than one thing
Examples:
Compound fracture
Compound sentence
Chemical compound

4. Examples of Chemical Compounds
H2O
C6H12O6
CO2
Pop Quiz!
Are CO and CO2 the same compound? CO = carbon monoxide, and CO2 = carbon dioxide

5. Examples of Chemical Compounds
H2O
C6H12O6
CO2
Pop Quiz!
Are CO and CO2 the same compound? CO = carbon monoxide, and CO2 = carbon dioxide
NO! They have different numbers of oxygen atoms. This makes them different compounds.

6. How are these atoms put together?
Chemical bonds – the attractive forces that hold different atoms or ions together
Chemical bonds can form between atoms and can also be broken
Na + Cl  Na-Cl (written as NaCl, bond formed)
NaCl  Na + Cl (bond broken)

7. Chemical formulas
Chemical formulas represent the numbers and types of atoms in a compound
A compound will always have the same chemical formula
Example:
H2O will always be water
NaCl will always be sodium chloride

8. Chemical Structure
The structure will differ between compounds based on the types of bonds between atoms.
Strong solids have network structures
All molecules in the structure are the same shape, including the angles of the atoms.
This arrangement holds the atoms together in a strong rigid structure.

9. Chemical Structure
The structure will differ between compounds based on the types of bonds between atoms.
Some compounds are networks made of bonded ions (ionic compounds)
Sodium chloride – Na+1 and Cl-1 ions are attracted to each other and form crystal-shaped structures
VERY strong bonds

10. Chemical Structure
The structure will differ between compounds based on the types of bonds between atoms.
Some compounds made of molecules (molecular compounds, also called covalent bonds)
Glucose - C6H12O6, not ions, but whole molecules attracted to each other to form crystals
Weaker bonds

11. How does bond strength affect a compound’s properties?
Network Structures
Ionic Compounds
Molecular Compounds/Covalent Bonds
VERY STRONG BONDS
High melting points (in the thousands)
High boiling points (in the thousands)
Strong bonds
High melting points (high hundreds to low thousands)
High boiling points (high hundreds to low thousands)
Weaker bonds
Lower melting and boiling points (usually less than 100)
Therefore, we can conclude that the stronger the bond, the more energy (high melting and boiling points) it takes to break the bonds. The weaker the bond, the less energy it takes to break the bonds.

12. Hydrogen Bonds Another force of attraction in compounds
Forms between adjacent hydrogen atoms of molecules
Strong bonds
Gives water special characteristics
Surface tension – the force between water molecules that gives it a droplet shape

13. Ch 5 Sec 1 Quiz Choose the term that best completes each sentence.
The atoms in a compound are held together by (chemical bonds/chemical structure).
A compound’s (chemical formula/bond angle) shows which atoms or ions it is made up of.
Network solids usually have (high/low) melting and boiling points.

14. Ch 5 Sec 1 Quiz Choose the term that best completes each sentence.
The atoms in a compound are held together by (chemical bonds/chemical structure).
A compound’s (chemical formula/bond angle) shows which atoms or ions it is made up of.
Network solids usually have (high/low) melting and boiling points.

15. What will we be learning?
Section 2: Ionic and Covalent Bonding
Explain why atoms sometimes join to form bonds.
Explain why some atoms transfer their valence electrons to form ionic bonds, while other atoms share valence electrons to form covalent bonds.
Differentiate between ionic, covalent, and metallic bonds.
Compare the properties of substances with different types of bonds.

16. Why do atoms bond together?
Valence electrons - which atoms have a full set of 8 electrons and do not need to lose or gain electrons?

17. Why do atoms bond together?
Valence electrons - which atoms have a full set of 8 electrons and do not need to lose or gain electrons?
Noble gases – they are stable
**Atoms form bonds to become stable**
The type of element and how many valence electrons it has determines what it can bond with.

18. Ionic Bonds Formed between oppositely charged ions
Example: Na+1 + Cl-1  NaCl
Characteristics of ionic bonds & compounds
Electrons are transferred (the chlorine atom GAINED the electron that the sodium atom LOST).
Usually between a metal and a nonmetal
Stronger than covalent bonds
High melting points and boiling points
Conduct electricity when dissolved in water
Can include polyatomic ions

19. Ionic Bonds
Polyatomic ions – a charged molecule that contains one or more types of atoms
Always put parentheses around a polyatomic ion and write the charge on the outside
The charge will never change
The types of atoms and subscripts will never change
Examples: P 158 Table 3

20. Formulas of Ionic Compounds
In order to write the formula for a compound, the charges must be determined.
Magnesium fluoride
Mg+2 + F-1 

21. Formulas of Ionic Compounds
In order to write the formula for a compound, the charges must be determined.
Magnesium fluoride:
Mg+2 + F-1  MgF2
“Switch and drop” the charges to make them subscripts, ignore the + or – signs.
If a Mg atom gives away 2 e-, a fluorine atom can only take 1 e- at a time, so Mg needs to bond to 2 F atoms.

22. Formulas for Ionic Compounds
Try it!
Sodium and Oxygen
Potassium and Chlorine
Magnesium and oxygen
Aluminum and oxygen
Remember: assign charges first, then switch and drop!

23. Formulas for Ionic Compounds
Try it!
Sodium and Oxygen: Na+1 + O-2 
Potassium and Chlorine: K+1 + Cl-1 
Magnesium and oxygen: Mg+2 + O-2 
Aluminum and oxygen: Al+3 + O-2 
Remember: assign charges first, then switch and drop!

24. Formulas for Ionic Compounds
Try it!
Sodium and Oxygen: Na+1 + O-2  Na2O
Potassium and Chlorine: K+1 + Cl-1  KCl
Magnesium and oxygen: Mg+2 + O-2  MgO (reduce!)
Aluminum and oxygen: Al+3 + O-2  Al2O3
Remember: assign charges first, then switch and drop!

25. Covalent Bonds Also called molecular bonds
Formed between atoms that are sharing electrons
Example: CH4 
Characteristics of Covalent bonds & compounds
Electrons are shared
Usually between two nonmetals
Weaker than ionic bonds
Lower melting and boiling points
Can have double bonds (sharing 2 e-) or triple bonds (sharing 3 e-)
Can be polar or nonpolar

26. Covalent Bonds
Sometimes covalent compounds share electrons equally, and sometimes they do not.
Polar covalent – a covalent molecule that has an unequal sharing of electrons
Example: H2O
Nonpolar covalent – a covalent molecule that has an equal sharing of electrons
Example: CH4
All the negativity (electrons) are toward one end of the molecule
The electrons are equally spread out around the atom

27. Metallic Bonds
Metallic bonds - A bond formed by the attraction between positively charged metal ions and the electrons around them
Characteristics of metallic bonds
Neighboring atoms in a sample of a metal packed together
Electrons are free to move from atom to atom and the atoms can slide past each other easily
This explains why metals conduct electricity and are able flexible

28. Ch 5 Sec 2 Quiz
Matching:
____ bond formed between positively charged metal ions and the surrounding electrons
____ bond formed between oppositely charged ions
____ bond formed between atoms that share electrons
A) Ionic B) Covalent C) Metallic

29. Ch 5 Sec 2 Quiz
Matching:
_C_ bond formed between positively charged metal ions and the surrounding electrons
_A_ bond formed between oppositely charged ions
_B_ bond formed between atoms that share electrons
A) Ionic B) Covalent C) Metallic

30. Bellwork Get yourselves into exactly SIX groups.
Each of you will have your own worksheet with your own responses.
I will assign which column your group will be doing. After the allowed time period, you will share with us your information!

31. What will we be learning?
Section 3: Compound Names and Formulas
Name simple ionic and covalent compounds.
Predict the charge of a transition metal cation in an ionic compound.
Write chemical formulas for simple ionic compounds.
Distinguish a covalent compound’s empirical formula from its molecular formula.

32. Ionic Compounds Name  Formula Formula  Name
Assign the charges to the atoms, “switch and drop”
Magnesium Fluoride  Mg+2 + F-1  MgF2
Formula  Name
Name the metal first, then change the ending of the nonmetal to –ide
Al2O3  Aluminum Oxide

33. Ionic Compounds w/Polyatomic Ions
Name  Formula
Assign the charges to the atoms, switch and drop
Use parentheses around the polyatomic ion
Aluminum hydroxide  Al+3 + (OH)-1  Al(OH)3
Formula  Name
Name the metal first, and the polyatomic ion second
Do NOT change any endings!
Mg(SO4)  Magnesium Sulfate

34. Ionic Compounds w/Transition Metals
The charges of transition metals can change
You can determine the charge of the transition metal by looking at its formula and what it is bonded with
REVERSE “switch and drop”!
Fe2O3  Fe+3 + O-2
FeO  Fe+2 + O-2
Predict!
What is the charge of the Cu if the formula is CuCl2?

35. Ionic Compounds w/Transition Metals
The charges of transition metals can change
You can determine the charge of the transition metal by looking at its formula and what it is bonded with
REVERSE “switch and drop”!
Fe2O3  Fe+3 + O-2
FeO  Fe+2 + O-2
Predict!
What is the charge of the Cu if the formula is CuCl2?
+2: Cu+2 + Cl-1  CuCl2

36. Ionic Compounds w/Transition Metals
The charge of a transition cation can also be told to you using Roman numerals
Copper(II) Sulfate  Cu+2 + SO4-2  CuSO4
Iron(III) Oxide  Fe+3 + O-2  Fe2O3

37. Covalent Compounds
Prefix system is used to tell how many of each type of atom there are in the compound
Change the ending to the second element to –ide
N2O4  Dinitrogen tetroxide
CO2  Carbon dioxide
Boron trifluoride  BF3
# of atoms
Prefix 1
Mono- 2
Di- 3
Tri- 4
Tetra- 5
Penta- 6
Hexa- 7
Hepta- 8
Octa- 9
Nona- 10
Deca-

38. Covalent Compounds
Some compounds have a reduced formula and a non-reduced formula
Empirical formula – simplest or reduced formula
CH2O = Empirical formula
Formaldehyde: CH2O
Acetic Acid: C2H4O2
Glucose: C6H12O6

39. Ch 5 Sec 3 Quiz
Which part of an ionic compound should be written first?
How can you tell what the charge is of a transition metal?
What kind of formula gives the numbers of atoms of each element in a compound in the simplest form?

40. Ch 5 Sec 3 Quiz
Which part of an ionic compound should be written first?
Cation, or the metal
How can you tell what the charge is of a transition metal?
Look at the molecular formula and what it is bonded with
What kind of formula gives the numbers of atoms of each element in a compound in the simplest form?
Empirical formula

41. Let’s Review! P 150 #1-5 (Section 1 Review)
P 161 #1-4 (Practice)
P 164 #1-6 (Section 3 Review)