1. Day 2 The Periodic Table
Sci 10
Chemistry

2. Try creating your own Periodic Table
Look at the cards of the first 18 elements. Can you group them in a way that makes sense?

3. Mendeleïev created the modern periodic table of the elements, placing the elements in order of increasing atomic mass.

4. Periods

5. Groups

6. Look back at your Periodic Table
Look at all of the models of elements in a Period (→)
What do they all have in common?
Look at all of the models of elements in a Group (↓)

7. Columns (vertical) of the periodic table are called GROUPS
Elements in a group share characteristics and properties because all have same # of electrons on outer shell
Rows (horizontal) of the periodic table are called PERIODS
Elements in a period all have the same amount of electron shell(s)

8. Métalloides

9. Metals and non-metals have different properties.
Metalloids have properties of metals and non-metals.

10. Alkali Metals – Group 1

11. Alkaline Earth Metals – Group 2

12. Transition Metals (metals with more than one charge)

13. Halogens – Group 17

14. Noble Gases – Group 18

15. Hydrogen – an exception
It can behave like an alkaline metal or like a halogen

16. Back to electrons… Electrons are located on shells around the nucleus
Different shells contain different number of electrons
Different elements have different numbers of shells
Valence shells: shell the farthest away from nucleus
Valence electrons : electrons on the valence shell

17. Period # indicates the # of electron shells:
Period 1 – 1 shell (2 e- max)
Period 2 – 2 shells :
shell #1 - 2 e- max
Valence shell (shell #2) – 8 e- max
Period 3 – 3 shells :
shell #2 – 8 e- max
Valence shell (shell #3) – 8 e- max

18. Bohr-Rutherford Diagram/ Electron shell diagram
An atomic model that shows the distribution of ALL electrons
Indicate the # of p+ and # of neutrons in nucleus (drawn as a circle)
Determine # of shells (# of period)
Add electrons (max 2 for the 1st, 8 for the 2nd and 8 for the 3rd)

19. Group # represents the # of valence electrons
(number of electrons in outer shell)
If group # greater than 10, subtract 10 to find the # of valence electrons

20. Lewis Structures/ Electron Dot Diagrams
A method of representing an atom that shows only its valence electrons
sodium carbon
chlorine

21. Practice!
p.97 #15, 18, 19
Day 2 - Questions