1. 4.2 Board Questions 1) Na3PO4 + KOH  NaOH + K3PO4
Balance the following equations
1) Na3PO4 + KOH  NaOH + K3PO4
2) MgF2 + Li2CO3  MgCO3 + LiF
3) P4 + O2  P2O3
4) CF4 + Br2  CBr4 + F2

2. 4.1 Board Questions What is a physical property?
Give an example
What are the three basic subatomic particles?
Which subatomic particle has a negative charge?
How many neutrons does Barium (Ba, #56) have?

3. 4.2 Board Questions Answer in complete sentences
Name 3 common compounds.
Are products on the left or the right of the arrow in a chemical equation?
What does a balanced equation mean?

4. 4.2 notes
Chemical Bonds

5. Atom – the smallest unit of matter “indivisible”
Helium
atom

6. electron shells Atomic number = number of Electrons
Electrons vary in the amount of energy they possess, and they occur at certain energy levels or electron shells.
Electron shells determine how an atom behaves when it encounters other atoms

7. Electrons are placed in shells according to rules:
The 1st shell can hold up to two electrons, and each shell thereafter can hold up to 8 electrons.

8. Octet Rule = atoms tend to gain, lose or share electrons so as to have 8 electrons
C would like to
N would like to
O would like to
Gain 4 electrons
Gain 3 electrons
Gain 2 electrons

9. Why are electrons important?
Elements have different electron configurations
different electron configurations mean different levels of bonding

11. Chemical bonds: an attempt to fill electron shells
Ionic bonds –
Covalent bonds –
Metallic bonds

12. IONIC BOND bond formed between two ions by the transfer of electrons

13. Formation of Ions from Metals
Ionic compounds result when metals react with nonmetals
Metals lose electrons to match the number of valence electrons of their nearest noble gas

14. Ionic Bond
Between atoms of metals and nonmetals with very different electronegativity
Bond formed by transfer of electrons
Examples; NaCl, CaCl2, K2O

15. Electronegativity
Electronegativity is a chemical property that describes the tendency of an atom or a functional group to attract electrons towards itself

17. Ionic Bonds: One Big Greedy Thief Dog!

18. Losing or Gaining
When an atom loses an electron it becomes more positive
When an atom gains an electron it becomes more negative

19. 1). Ionic bond – electron from Na is transferred to Cl, this causes a charge imbalance in each atom. The Na becomes (Na+) and the Cl becomes (Cl-), charged particles or ions.

20. COVALENT BOND bond formed by the sharing of electrons

21. Covalent Bond
Between nonmetallic elements of similar electronegativity.
Formed by sharing electron pairs
Examples; O2, CO2, C2H6, H2O, SiC

22. Covalent Bonds

23. when electrons are shared equally
NONPOLAR COVALENT BONDS
when electrons are shared equally
H2 or Cl2

24. 2. Covalent bonds- Two atoms share one or more pairs of outer-shell electrons.
Oxygen Atom
Oxygen Atom
Oxygen Molecule (O2)

25. when electrons are shared but shared unequally
POLAR COVALENT BONDS
when electrons are shared but shared unequally
H2O

26. Polar Covalent Bonds: Unevenly matched, but willing to share.

27. - water is a polar molecule because oxygen is more electronegative than hydrogen, and therefore electrons are pulled closer to oxygen.

28. Double-door fold notes
P. 96
Create a double-door fold
Label one door “ionic bond” and the other door “covalent bond”. Write notes about these terms behind each door.

29. Homework
P. 98 #1-7