1. Topic 3 Lesson 3 New Book EQ: What causes atoms to bond?
Atoms & Bonding
Topic 3 Lesson 3
New Book
EQ: What causes atoms to bond?

2. Valence Electrons Determines properties of the element
Determines the ways the atom can bond with other atoms
Each element has between 1 to 8
Electron Dot Structure: shows the number of valence electrons in an element
Chemical symbol
Valence electron #

3. The Periodic Table
Elements in the same group/family have the same number of valence electrons
Group 1/Alkali metals: 1 valence electron
Group 2/ Alkali earth metals: 2 valence electrons
We skip transition metals and Helium (they are harder to predict.
Group 13: 3 valence electrons
Group 14/Carbon family: 4 valence electrons
Group 15/Nitrogen family: 5 valence electrons
Group 16/Oxygen family: 6 valence electrons
Group 17/Halogens: 7 valence electrons
Group 18/Noble or Inert gases: 8 valence electrons
Last number in group = # of valence electrons

6. Electron Dot Structure Practice
Oxygen
Potassium
Krypton
Aluminum
Phosphorus
Remember:You begin the diagram by adding dots on the right side and continuing in a counter-clockwise direction

7. Stability 8 valence electrons = stable
Which group/family is already stable?
Halogens have 7 valence electrons….how many more do they need?
React with elements who can give or share one electron….alkali metals.
What is one common compound made from a halogen and an alkali metal?

8. Bonding and Periodic Properties
Metals
Most elements are made of metal
Both chemical and physical properties are determined by their valance electrons
The easy movement of valance electrons in metals is what makes metals malleable or ductile

9. How the element combines or reacts is based on the interactions of valance electrons
Generally have one to three valance electrons
Metals do not react with other metals, but they react with other elements
Highly reactive- tends to lose valence electrons

10. Bonding and Periodic Properties
Non-metals
Atoms of nonmetals react with both metals and nonmetals
Levels of reactivity are based on the number of valance electrons
Halogens are highly reactive (7) and Noble Gases are non-reactive (8)

11. Bonding and Periodic Properties
Metalloids
Has some properties of metals and some properties of nonmetals
Located along the stair step line between the metals and non-metals

12. Valence Electrons and Bonding
Metals- lose electrons
Nonmetals- gain electrons
Elements with 1, 2, or 3 valence electrons lose electrons during bonding
Elements with 4 valence electrons gain or lose
Elements with 5, 6, or 7 valence electrons gain valence electrons

13. Electrons are NEGATIVELY CHARGED
When an element loses electrons, it becomes positive
When an element gains electrons, it becomes negative

14. Examples:
Group 1 elements lose ______ valence electron which makes the charge +1
Group 2 elements lose 2 valence electrons which makes the charge ___________
Group 7 elements gain ______ valence electron which makes the charge -1

15. Elements in group 1 lose electrons and elements in group _________ want to gain 1 electron to become stable.
Example:
Sodium Cholrine (-ide)

16. Chemical Bond