The document introduces the periodic table and discusses how it is organized. It explains that elements are arranged by atomic number vertically into groups and horizontally into periods. [The document] instructs the reader to draw electron configuration diagrams for the first 20 elements and observe that elements in the same group have the same number of valence electrons. It also notes that elements in the same period have the same number of electron shells. In conclusion, [the document] emphasizes that the number and arrangement of valence electrons determines how an element bonds and reacts chemically.

1. Compounds and
Bonding
Introduction to Ionic Bonding
The Periodic Table

2. First a review of the

3. Elements are arranged by atomic number
Vertically
into Groups
Horizontally Into
Periods

4. Draw electron configuration diagrams to show the electron
arrangements for these elements on the periodic table provided
remember 2,8,8,2
Do this for the first
twenty elements
before the next slide.

5. Make a conclusion: Look at the
diagrams you drew for each group . . .
Each atom has the same number of
electrons in it’s outermost shell.
These electrons are called valence
electrons. Valence electrons determine
how an element will form chemical
bonds and react.

6. For example - the Group 2 elements all have 2
valence electrons.
Be (Beryllium)
Atom
Mg (Magnesium) Atom

7. • The number of outer or “valence” electrons in an
atom effects the way an atom bonds.
• The way an atom bonds determines many properties
of the element.
• This is why elements within a group usually have
similar chemical properties.
For example alkali (group 1) metals all
react with water to produce hydrogen gas

8. If you looked at an atom from each element in
a period
What do you see…
Each atom has the same number of
electron holding shells.

9. For example: the period 4 atoms each have 4 electron
shells
4
K (Potassium) Kr (Krypton)
Atom Atom
Fe (Iron) Atom

10. Now, use a different color and write the 2,8,8,2
electron arrangements for the first 20 elements on
your handout.
1 2
2,1 2,2 2,3 2,4 2,5 2,6 2,7 2,8
2,8,1 2,8,2 2,8,3 2,8,4 2,8,5 2,8,6 2,8,7 2,8,8
What do you observe?
2,8,8,1 2,8,8,2
The last number in the electron arrangement
indicates the number of valence electrons.
This is the same for all elements in a group.

11. Other useful things to know
about the Periodic Table

12. Solids, liquids and gases
(at room temperature)

13. Metals, metalloids and non-metals

14. Alkali Metals
Soft, silvery colored
metals
Very reactive!!!

15. Alkaline Earth Metals
Silvery-White Metals
Fairly reactive
Many are found in rocks in
the earth’s crust

16. Transition Metals
Most are good Malleable (easily
Conductors of bent/hammered into
electricity wires or sheets)

17. Halogens
Poisonous
Reactive

18. Noble Gases
Unreactive
Mono-atomic
Gases at room
temperature