1. Chapter 3
Matter in action

2. What are the three types of Change?

3. Transformation of matter
Physical change: Does not change the type substance

4. Chemical change (chemical reaction)
composition of a substance is altered

5. Signs of chemical change
Change in colour (e.g iron rusting)
Gas being released( baking soda and vinegar)
Light or heat being given off
Change in smell

6. Chemical Change Involve the electrons in the outermost shell
The outermost electrons are called valence electrons

7. Nuclear change
Occurs within the nucleus of the atom; the number of protons and neutrons changes

8. Bonds between atoms Bonded atoms are called molecules
Same type of atom (O2)= element
2 or more different types of atoms = compound

9. Molecular formulas Write down the elemental symbols
Use subscripts to indicate how many of each element after it’s symbol

10. Why do atoms react?
Think electrons

11. How and why atoms react? Noble gases are most stable, do not react
They have complete outer shells (8 valence electrons)
All elements bond in order to resemble the nearest noble gas

13. Ionization
The loss or gain of electrons

14. Ions- atoms that have lost or gained electrons
Anions are negative
Cl + 1e- → Cl-
Cations are positive
Ca → Ca2+ + 2e-

15. Finding Charge Protons are positive Electrons are negative
Therefore subtract electrons from protons.
examples

16. The Lewis Diagram

17. P
#1 and #2

18. Examples

19. Ions with Lewis Dot

20. Chemical Bonds
Covalent bonds
Ionic bonds

21. Ionic bonds Electrons are “stolen”
One atom takes the electrons and becomes negative
One atom loses the electrons and becomes positive

22. Ionic Bonds Normally a combination of metals and non-metals.
Who will gain?
Halogens will gain, you are more likely to pick 1 electron than lose 7.
Who will lose?
Alkalies and alkaline earth metals. You are more likely to give up one or two electrons than gain 6 or 7.

25. P. 188 # 5-6-7

26. Charge associated with Ion
Group IA has a charge of +1, because it will want to loose an electron.
Group IIA has a charge of +2 it will want to give up two electrons
Group IIIA has a charge of +3
Group VA will have a charge of ____________
Group VIA will have a charge of ___________
Group VIIA will have a charge of __________

27. Assign a charge to each of the following atoms
O P B Br Na Cl Mg Al

28. The Crossover Rule
Helps determine the molecular formula of ionic compounds
Steps:
Write element symbols with their ionic charges
charges go to the bottom of the opposite element. (no sign on bottom)

29. P.188 #8
P.189 #9

30. Covalent bonds Electrons are shared between the 2 atoms
Have structural formula

32. When and why?
Elements that are far apart on the periodic table (non-metal and a metal) will bond ionically
Elements that are close together on the periodic table will bond covalently. ( 2 non-metals)

34. P. 190 # 10-11

35. Or use Electronegativity
Small number in right hand corner of periodic table
Subtract the numbers for the two elements in the compound
E.g. Na = 0.9, Cl = 3.0
3.0 – 0.9 = 2.1
1.7

36. P. 186 # 1-2
P 187 # 3-4

37. P.207 #1 to 4
P.208 #5 to 8

38. Molecular structure
Only occur in Covalent bonds