1. Periodicity &
the Periodic Table

2. The Atom in 1869 – Dmitri Mendeleev The First “Modern” Periodic Table

3. The Atom in 1869 – Dmitri Mendeleev
Mendeleev’s “Periodic” Atomic Theory
Elements of similar atomic mass display similar properties
Elements with atomic masses that increase in equal increments display similar properties
The elements can be arranged 2-dimensionally by their properties to predict “missing” elements.
Think you’re as smart as Mendeleev?

4. Think you’re as smart as Mendeleev?
Periodicity
I’m a genius!
Elements display repeating patterns based on their properties when arranged into a 2-dimensional grid
Think you’re as smart as Mendeleev?

5. The basic idea: arrange cards so that patterns and trends follow logical orders across and up/down your table. Find missing boxes by finding "gaps" in the trends. Predict what's missing. B1 B2 A2 C1 C2 B3 D1 D2 A1 D3 A3

6. The basic idea: arrange cards so that patterns and trends follow logical orders across and up/down your table. Find missing boxes by finding "gaps" in the trends. Predict what's missing. A1 B1 C1 D1 A2 B2 C2 D2 A3 B3 D3

7. The basic idea: arrange cards so that patterns and trends follow logical orders across and up/down your table. Find missing boxes by finding "gaps" in the trends. Predict what's missing. A1 B1 C1 D1 A2 B2 C2 D2 B3 C3 A3 D3

8. Alien Periodic Table
Arrange the cards you have been given into a grid- It will be a rectangle
Aliens that demonstrate similar properties are adjacent- either side to side or under and over.

9. The Modern Periodic Table

10. The Modern Periodic Table What it REALLY looks like!

11. GROUPS Remember periodicity? How do Groups relate to periodicity?
Group Numbers
Remember periodicity? How do Groups relate to periodicity?
NO Group Numbers
(Names Only)

12. PERIODS
Period Numbers
And how does periodicity relate to periods?

13. 6.2 Classification of the Elements
Elements can be classified into four categories based upon their electron configurations
Noble gases
He, Ne, Ar, Kr, Xe, and Rn
Full outer s and p sublevels
Representative elements
Groups 1A – 8A (this includes Noble Gases)
Partially filled s and p sublevels

14. 6.2 Classification of the Elements
Transition metals
d block
Outer s and nearby d sublevel contain electrons
Inner transition metals
f block
Outer s and nearby f sublevel contain electrons

15. Representative Elements Inner Transition Metals
Noble Gases
Transition Metals
Representative Elements
Inner Transition Metals

16. GENERAL CATEGORIES
Yeah. You gotta know ‘em.

17. General Properties
Usually, metals are:
Conductive
Shiny
Malleable
Ductile
Solid at room temperature
(can you think of an exception?)
The Alkali Metals are particularly interesting:
Very soft, cut with a knife
Highly reactive with air and water

18. Usually, non-metals are: Insulators Dull Brittle
General Properties
Usually, non-metals are:
Insulators
Dull
Brittle
Often gaseous at room temperature
The Noble Gasses are particularly interesting:
Exceptionally Nonreactive
The Halogens are also very interesting:
Tend to form diatomic molecules
Highly reactive with almost everything

19. General Properties
Metalloids:
Some are like metals
Some are like non-metals
Properties vary greatly within a group

20. FAMILIES
Yeah. You gotta know ‘em.

21. What is similar for all elements in a group or family?
These have 1
These have 3
They have the same number of outer level electrons!!!

22. Classification of the Elements
Electrons, particularly the valence electrons, control many of the chemical and physical properties of atoms!

23. ALL TRENDS ARE EXPLAINED BY NUCLEAR CHARGE AND SHELLS AND SHIELDING
6.3 Periodic Trends
Because the arrangement of elements on the periodic table is closely linked to the electron configuration, there are a number of trends that can be used to predict chemical and physical behavior.
In order to understand and use these trends, you must first understand how NUCLEAR CHARGE and SHELLS AND SHIELDING influence electron behavior.
ALL TRENDS ARE EXPLAINED BY NUCLEAR CHARGE AND SHELLS AND SHIELDING

24. 6.3 Periodic Trends Nuclear Charge
As you move across a period or down a group, the atomic number increases.
This means the number of protons in the nucleus is increasing.
With more protons, the positive pulling strength (nuclear charge) of the nucleus is increasing

25. Nuclear Strength
Increases
Increases

26. 6.3 Periodic Trends Shells Shielding Energy levels
The higher the level, the farther from the nucleus
Across – highest energy does not change
Down – energy levels increase
Shielding
Inner level electrons interfere or shield the valence electrons from the nucleus
Across – shielding is constant
Down – shielding increases

27. Shells and Shielding
Constant
Increases

28. Nuclear Charge verses Shells and Shielding
Period Trend
Nuclear Strength Wins!!!
Because Shells and Shielding are constant across a period they don’t affect period trends
Therefore, ALL PERIOD TRENDS are caused by increasing nuclear charge.

29. Nuclear Charge verses Shells and Shielding
Group Trend
Shells and Shielding Win
Even though nuclear charge is increasing, more Shells (your farther from the nucleus) and Shielding (inner level electron interference) decreases the effective nuclear strength.
Therefore, ALL GROUP TRENDS are caused by shells and shielding or their effect on the nuclear charge.

30. Nuclear Charge verses Shells and Shielding
S/S Increases lowering effective Nuclear Strength
Nuclear Strength Increases

31. Atomic Radius
Atomic radius – estimated as ½ the distance between the nuclei of 2 like atoms in a diatomic molecule.
As atomic radius increases, the element increases in size.

32. Atomic Size

33. Atomic Size
Size Increases
Size Decreases

34. Ion Formation Metals will lose electrons Nonmetals gain electrons
Octet Rule – atoms will gain or lose electrons (sometimes even sharing like in molecules) to acquire a full set of 8 valence electrons.
Metals will lose electrons
Nonmetals gain electrons

35. Two hydrogen atoms are walking down the street.
Hey, I think I just lost an electron!
Are you sure!
Yeah!
I’m POSITIVE!

36. The Cation is smaller than the neutral atom!
Ion Formation
Cation – formed when electrons are removed from a neutral atom
Nucleus has a stronger pull on the remaining electrons decreasing the size
The Cation is smaller than the neutral atom!

37. The Anion is larger than the neutral atom!
Ion Formation
Anion – formed when electrons are added to a neutral atom
Nucleus has a weaker hold on the increased number of valence electrons and the ion size increases
The Anion is larger than the neutral atom!

38. Ion Size Period Trend Group Trend
Cations and Anions both decrease in size across a period
Group Trend
Cations and Anions both increase in size down a group

39. Ionic Size
Cations decrease
Anions decrease
Both increase

40. Ionization Energy Na(g)  Na+(g) + e-
Ionization energy – energy needed to remove an electron from an atom
Na(g)  Na+(g) + e-

41. Ionization Energy
To remove an electron you have to overcome the nucleus’ hold on the electron.
1st Ionization Energy – Energy needed to remove first electron.
2nd Ionization Energy – Energy needed to remove a second electron.
This is always higher than the 1st ionization energy.
When an electron is removed, the nucleus has a stronger hold on the remaining electrons.
When you have a noble gas electron configuration it becomes very difficult to remove an electron.

42. Ionization Energy

43. Ionization Energy Group Trend Period Trend
Decreases as you go down a group
The farther the outer electrons are farther from the nucleus, the weaker the pull.
The inner level electrons block the nucleus’ ability to attract the valence electrons.
Period Trend
Increase as you go across a period

44. Ionization Energy 1st Ionization Energy decreases
1st Ionization Energy increases

45. Electronegativity
Electronegativity – attraction of one atoms nucleus to another atoms electrons when they are chemically bonded
Measure of how strong the oxygen nucleus attracts the hydrogen’s electron H H O
Water Molecule

46. Electronegativity H 2.1 Li 1.0 Be 1.5 B 2.0 C 2.5 N 3.0 O 3.5 F 4.0 NaLi
1.0 Be
1.5 B
2.0 C
2.5 N
3.0 O
3.5 F
4.0 Na
0.9 Mg
1.2 Al Si
1.8 P S Cl K
0.8 Ca Ga
1.6 Ge As Se
2.4 Br
2.8 Rb Sr In
1.7 Sn Sb
1.9 Te I Cs
0.7 Ba Tl Pb Bi

47. Electronegativity Period Trend Group Trend Increases across a period
Greater hold on electrons
Group Trend
Decreases down a group
Weaker hold on the electrons

48. Electronegativity Electronegativity increases
Electronegativity decreases
Electronegativity increases

50. Designing A Periodic Table Activity
Arrange the cards you’ve been given into a grid. Your grid may or may not be perfectly square.
Atoms with similar properties are adjacent, either side to side or over and under.
There may be “gaps” where an element should be to make the similarity of properties make sense. Put your blank card in the gap.
When you’ve found the missing element, interpolate its properties from its neighbors