1. Warm up
An element is dull, silvery in color, can be cut with a knife and is very reactive in water. What family could this be in?

2. Properties of Atoms and the Periodic Table

3. Structure of the Atom

4. Atomic Compounds
Atom—smallest piece of matter that still retains the property of the element
Element of silver=only atoms of silver
Element of hydrogen=only atoms of hydrogen
Atoms are composed of sub-atomic particles called protons, electrons, and neutrons.

5. Electron Cloud Model-
current model
Electrons don’t follow fixed orbits
Area around the nucleus where electrons are most likely found

6. Electron Cloud Model
Electron Cloud—area around the nucleus of an atom where its electrons are most likely found
Energy level-areas of the cloud where the electrons are more likely to be found

7. Energy Levels
Electron Cloud: electrons orbit the nucleus in patterns, rings
Closer to the nucleus= low energy
Further from the nucleus= high energy

8. Energy Levels
Each energy level has a maximum number of electrons it can hold:
Energy Level
Maximum Electrons 1 2 8 3 18 4 32

9. Octet Rule
In the 1st three energy levels the electrons will not begin to fill the next energy level until the previous one is full
Octet Rule: 8 electrons makes an energy level full and stable
Less than 8 is unstable
Electrons will try to bond with other elements so they have 8 electrons in their outer level.

10. Valence Electrons
Valence Electrons are the electrons in the last shell or energy level of an atom
Show a repeating pattern across the periodic table
Valence electrons increase in number as you go across a period on the periodic table

11. Valence Electrons
Are located furthest from the nucleus (have the most energy)
Electrons responsible for the bonding of elements to form compounds

12. Visualizing Electrons in Atoms
Two ways to diagram electrons and bonding in atoms:
Bohr Diagrams
Lewis Dot Structures/Electron Dot Diagram H Cl
Dots represent Electrons

13. Bohr Diagrams
Bohr Diagrams are a way to represent the number of electrons in an element
In Bohr Diagrams the number of electrons are represented in orbits around the nucleus (protons and neutrons)

14. Lewis Dot/Electron Dot
Lewis dot structures represent the number of electrons in the outer energy level
The number of valence electrons for each element must be known to construct the structures

15. Lewis Dot/Electron Dot
You can use Lewis Dot structures to visualize how bonds are made between elements forming compounds
The valence electrons are the electrons that are gained, lost, or shared

16. Ne To construct Lewis Dot Structures: Identify the valence electrons
Construct the Bohr diagram if you do not know the # of valence electrons
Write the chemical symbol
Use dots to represent the valence electrons; place the electrons around the symbol in the order to the right 1 5 Ne 8 2 4 6 7 3

18. Organizing the Elements
Periodic means “repeated in a pattern”
Dmitri Mendeleev (1869): arranged the elements in order by increasing atomic masses

19. Organizing the Elements
Periodic Table: the elements are arranged by increasing atomic masses and by changes in physical and chemical properties

20. Groups/Families Vertical columns (1-18)
Represents the number of valence electrons
Atoms have similar properties
Atoms become more reactive as you move down a column

21. The Group numbers on top and form columns for “groups” or “families”1 18 2 13 14 15 16 17 3 4 5 6 7 8 9 10 11 12
This is group 1 the alkali group. Families have similar but not identical characteristics

22. Periods Horizontal rows on the periodic table
Represent the # of energy levels

23. Periods run down the side and form rows of “periods”1 2 3 4
This is period
number 3 Which means it has 3 energy levels 5 6 7

24. Periods Represent the Number of outer rings
Or what scientists call “energy Levels” of electrons
Energy Level 1: H & He
Locate them on your periodic table
electron

25. Periods Represent the Number of outer rings
Or what scientists call “energy Levels”
Energy Level 2: Li, Be, B, C, N, O, F & Ne
Locate them on your periodic table

26. Periods Represent the Number of outer rings
Or what scientists call “energy Levels” of electrons
Energy Level 3: Na, Mg, Al, Si, P, S Cl & Ar
Locate them on your periodic table

27. Atomic Size
As you move across the table (period), the atoms size generally gets smaller
As you move down the table (group), the atoms radius generally gets bigger

29. Metals
increase in reactivity Fr
Increase in reactivity

30. Metals Malleable—can be hammered into sheets
Ductile—can be drawn into wires
Shiny
High melting/boiling points
Good conductors of heat and electricity
Radium-Boiling point is 1140 C

31. Nonmetals

32. Nonmetals Dull, brittle, powdery Low melting/boiling points
Carbon
Dull, brittle, powdery
Low melting/boiling points
Poor conductors of heat and electricity
Can be solid, liquid, or gas
Sulfur
Chlorine
Bromine

33. Metalloids

34. Metalloids Have properties of both metals and nonmetals Semi-metals
Antimony
Boron

35. Alkali Metals

36. Alkali Metals Group 1 Valence electron: 1 Highly reactive solids
Only found as compounds
Ex: sodium (Na)—found in soap and drain cleaners

37. Hydrogen “Special Element” Valence Electron: 1
Has properties of alkali metals
…..but it is a
NON-METAL

38. Alkaline Earth Metals

39. Alkaline Earth Metals Group 2 Valence electrons: 2 Highly reactive
Not found free in nature
Combine easily with nonmetals to form salts

40. Transition Metals

41. Transition Metals
Group 3-12
Valence electrons: vary
Properties vary

42. Halogens

43. Halogens Group 17 Valence electrons: 7
Called “salt formers”—combine easily with groups 1 & 2
Only group to have all 3 states of matter (solid, liquid, gas)
Chlorine Gas

44. Noble Gases

45. Noble Gases Group 18 Valence electrons: 8
Very stable (electrons are in low energy states)
Have everything they need “Noble”
Very unlikely to bond with any other elements
Inactive gases

46. Lanthanide
Series
Actinide
Series

47. Lanthanide/Actinide Synthetic Elements Man-made elements
Can be found in smoke detectors