1. Chapter 5: The Periodic Table
5-1 Development of the Periodic Table
5-2 Reading the Periodic Table
5-3 Periodic Trends

2. 5-1Developement of the Periodic Table
State the periodic law
Discuss contributions that Dobereiner, Newlands, Mendeleev, and Mosely made to the periodic table

3. What do you organize?
The development of the periodic table was one of the biggest achievements of chemistry
It brought order to thousands of ideas and what seemed like unrelated facts
It helped chemists predict the existence of elements that hadn’t been discovered yet

4. Forerunners of the Periodic Table
1790’s - only knew of 23 elements
1800’s - Introduction of electricity helped break compounds down into elements scientists didn’t know existed.
mid-1800’s Industrial Revolution – new chemistry related industries
known elements

5. Forerunners of the Periodic Table
J.W. Dobereiner ( )
In early 1800’s classified elements into groups of three
Could see a pattern of similar traits
Called the sets, triads
Example: lithium, sodium, potassium calcium, strontium, barium chlorine, bromine, iodine
Placed them in this order b/c the middle element has a mass equal to the average masses of the other 2
atomic mass of Br = 79.9
avg atomic mass of Cl and I = ( )/2 = 81.2

6. Forerunners of the Periodic Table
J.A.R. Newlands ( )
In 1865, first to see a pattern
Realized the elements’ properties were repeating after every 8th element
Called the pattern the law of octaves after the music scale
Pointed out the was a repetition or “periodic” trend to the properties

7. Forerunners of the Periodic Table
Dmitri Mendeleev ( ) and Lothar Meyer ( )
In 1869, published nearly identical classification methods
Mendeleev’s is more well known
Classified elements by their atomic masses

8. The Periodic Law Henry Moseley (1887-1915)
Student working in Rutherford’s lab
In 1913, reorganized the periodic table according to atomic numbers

9. The Periodic Law States:
When elements are arranged in order of increasing atomic number, their physical and chemical properties show a periodic pattern

10. Section Review Restate the Periodic Law in your own words
How were Dobereiner and Newlands’ ideas helpful in creating the periodic table?
What did Moseley’s work contribute to the development of the periodic table?
Which property did Mendeleev arrange his periodic table?

11. 5-2 Reading the Periodic Table
Explain why elements in a group have similar properties
Identify the four blocks of the periodic table

12. Organizing the Squares
Groups: columns
Periods: rows

13. Labeling and Naming Groups
Alkali metals: group 1
Alkaline earth metals: group 2
Halogens: group 7
Noble gases: group 8
Transition metals: groups in the middle

14. Metals, Nonmetals, and Metalloids
Metals: most of the elements on the table
Great conductors of electricity
Malleable (able to hammer into thin sheets)
Ductile (able to be made into wires)
Very shiny

15. Metals, Nonmetals, and Metalloids
Upper right hand corner of table
Usually gases
Neon
Bromine

16. Metals, Nonmetals, and Metalloids
Have a combo of metal and nonmetal properties
Elements that touch the stair step line
Exceptions: boron and aluminum

17. Practice Problems For the following elements find: the element symbol
atomic number
classify it as a metal, nonmetal, or metalloid
name the group it is in if it has one
Iodine
Magnesium
Gold
Lithium
Argon
Chlorine
Barium
Cesium
Strontium
Silicon
Xenon

18. Label your periodic table
activity

19. Electron Configuration and the Periodic Table
Take a look:
Period 1 hydrogen 1s1
Period 2 lithium 1s22s1
Period 3 sodium 1s22s22p63s1
Period 4 potassium 1s22s22p63s23p64s1
What do they have in common?
A single electron in their outside orbital

20. Electron Configuration and the Periodic Table
Valence electrons: electrons in the highest principle energy level
How many valence electrons does Be have? 2
How many valence electrons does Mg have?
How many valence electrons does Ca have?

21. Electron Configuration and the Periodic Table
Atoms in the same group have similar chem properties because they have the same # of valence electrons
Elements in group 1A have one valence e-
Elements in group 2A have two valence e-
Elements in group 8A have eight valence e-

22. Electron Configuration and the Periodic Table
The period number and the principle energy level number are equal to each other
Li: period 2 and its e- config
1s22s1
Ga: period 4 and e- config.
1s22s22p63s23p64s23d104p1
What is the e- config. for the group 1A element in the 6th period?
1s22s22p63s23p64s23d104p65s24d105p66s1

23. The s-, p-, d-, and f-block Elements
s-block elements
Groups 1A and 2A plus hydrogen and helium
Group 1A: have one valence electron and the electron config. ends in s1
Group 2A: have two valence electrons and the electron config. ends in s2
Because only 2 e- fit in the s orbitals, there are only two “s” groups

24. S block

25. The s-, p-, d-, and f-block Elements
p-block elements
Filled after the s sublevel
Groups 3A – 8A
Group 8A elements are incredibly stable b/c both the s and p orbitals are filled

26. p-blocks
s-blocks

27. The s-, p-, d-, and f-block Elements
d-block elements
Contains transition elements
d orbitals can fit up to 10 electrons so there are a total of 10 groups
Group B elements

28. p-blocks
s-blocks
d-blocks

29. The s-, p-, d-, and f-block Elements
Inner transition metals
f orbitals can hold up to 14 electrons so there are 14 groups/columns

30. p-blocks
s-blocks
d-blocks
f-blocks

31. 5-3 Periodic Trends Define the term periodic trend
Identify 4 important periodic trends and explain how each reflects the electron configurations of the elements

32. Atomic Radius
Half the distance b/w the nucleus of one atom and the nucleus of the closest atom next to it d 2

33. Atomic Radius Trends in periods Trends in groups
Decreases as you go right
Trends in groups
Increases as you go down

35. Ionic Size Atoms can gain and lose electrons
When they do, they form ions
When they lose e-, they grow smaller
When they gain e-, they grow larger
Trends within periods
Decrease as you move right until Nitrogen
Trends within groups
Increase as you move down

37. Ionization Energy
Energy needed to remove an electron from an element/atom
The more electrons you remove, the more energy is needed
Trends within periods
Increase as you move right
Trends within groups
Decrease as you move down

39. Practice Problems
Boron, carbon, and aluminum occur near each other in the periodic table, which is the largest? Which has the highest ionization nrg?
Al is largest and C has highest ionization nrg
Which of the following atoms is smallest: lithium, beryllium, or magnesium? Which has the highest ionization nrg?
Be is smallest and has highest ionization nrg
Which of the following is the largest: a sodium atom, a sodium atom with a +1, or a potassium atom?
K atom

40. Octet rule
Atoms tend to gain, lose, or share electrons in order to get a full set of eight electrons
Atoms will do anything to get these eight

41. Electronegativity
The relative ability of atoms to attract electrons to themselves
Trends within periods
Increases as you move right
Trends within groups
Decreases as you move down