1. Do Now Get out your homework: Page 8 practice # 1 Page 9 practice #5
2. Check page 10 practice #6
Look at the back of the textbook.

2. Answers Page 8 practice # 1
Protons are found in the nucleus and have a positive charge. The # of protons is the same as the atomic number.
Neutrons are found inside the nucleus and have no charge. They add mass to the atom.
Electrons are found surrounding the nucleus and have a negative charge. They play a role in bonding.

3. Answers Pg. 9 # 5 4e- 2e- a) Carbon 6p+ 6no 1e- 1p+ b) Hydrogen 0no
c) Aluminium

4. Answers Pg. 9 # 5 1e- 2e- d) lithium 3p+ 4no 1e- 8e- 2e- e) sodium
f) fluorine
7e-
2e-
9p+
10no

5. Answers Pg. 9 # 5 Pg. 10 #6 is in the back of the textbook 8e- 2e-
10no
g) neon
2e-
2p+
2no
h) helium
Pg. 10 #6 is in the back of the textbook

6. A1.1 The Structure of Matter

7. The Plan Go over pg. 5 & 6 of work booklet.
Review valence electrons, Bohr & Lewis dot diagrams.
A1.2 Atomic bonding and properties
Work on summative assignment.

8. A1.2 Atomic Bonding & Properties
Science 20
Unit A

9. Review-Valence Electrons
An electron that occupies the outermost energy level in an atom.
It is these electrons that determine the chemical properties of an atom.
Atoms of different elements that have similar electron arrangements have similar characteristics and are arranged in families.
All atoms strive to complete the outer shell with electrons and thus become a stable atom. They can complete these outer shells by gaining, losing or sharing electrons from other atoms.

10. Metals vs. Non-Metals
Metals tend to form positively-charged ions (cations)
Non-metals tend to form negatively-charged ions (anions)

11. Aluminum
Is a metal that has luster, good heat and electrical conductivity, is malleable and ductile and tends to form positive ions.
A non-metal is not flexible, does not conduct well and tends to form negative ions.

12. Rock Salt
Is a compound which is made up of elements (sodium & chlorine).
If one element is a metal & the other is a non-metal then the compound is called an ionic compound and the bond between a positive & a negative ion is called an ionic bond.

14. Metals + Non-Metals = ionic bonds

15. Sharing Electrons
Two or more non-metallic atoms tend to share electrons to complete the outer shell.
By sharing they form covalent bonds.

16. Plastics Composed of hydrogen & carbon, which are both non-metals.
If two non-metals combine they form molecular compounds. The bonding does not involve ions, rather a sharing of electrons and the bond is called a covalent bond.
The resulting compound is called a molecule.

17. Covalent Bonds
Nonmetal + Nonmetal = covalent bonds

18. In General
Bonds formed by molecular compounds are weaker than ionic compounds.
The properties of the categories of matter, on pg. 21 of your text, can explain:
Why molecular compounds will melt quicker than ionic compounds
Why ionic crystals will snap if you try bending them, while molecular compounds will bend
Why metals conduct better
Why molecular compounds can dissolve

19. Assignment Practice problems #2, 3, & 9 (p. 14) Read pgs. 15-23
1.2 Questions: Pg #1-5
Diagrams of Atoms Summative Assignment–Due Monday, February 8th.
Skip pg. 6 of notebook?