2. The Periodic Table

3. Why is the Periodic Table important to me?
Useful tool for chemists
Helps us predict the physical and chemical properties of an element based on its location (row and column)

4. Before the table was developed…
Element organization was a mess.
Imagine going to a grocery store with no organization!!
Difficult to find information.
Chemistry didn’t make sense.
Dalton 1800’s
Gmelin 1843

5. Chancourtois (1862) and Newland (1863)
Organized by increasing atomic masses, and observed a repeating pattern to the properties of the elements, but this pattern fell apart after Calcium.

6. Dmitri Mendeleev: Father of the Table
Russian Chemist
Mendeleev observed the relationship between the elements increasing atomic mass and repetitive pattern of physical and chemical properties.
Published the first version of the periodic table in 1869

7. Mendeleev’s Table Gaps existed in his table (marked with a “?”)
He was able to predict the properties of these missing elements long before they were discovered.

8. Mendeleev’s Predictions
“Ekasilicon”
Germanium
Notice how Mendeleev’s
predictions (orange column) were very
accurate when compared to Germanium’s actual characteristics (green column)
Date Predicted
1871
Date Discovered
1886
Atomic Mass 72
72.6
Density
5.5 g/cm3
5.47 g/cm3
Bonding Power 4
Color
Dark Gray
Grayish White

9. Put elements in rows by increasing atomic mass.
How his table worked:
Put elements in rows by increasing atomic mass.
Put elements in columns by the way they reacted.
Some Problems:
He left blank spaces for what he said were undiscovered elements.
He broke the pattern of increasing atomic weight to keep similar reacting elements together.

10. Periodic Law
Mendeleev stated that the physical and chemical properties of elements repeated according to a pattern. Similar elements were placed in the same column.

11. Henry Moseley ( )
Made improvements to Mendeleev’s Periodic Table
Moseley discovered that the periodic nature of the elements wasn’t due to atomic mass, but by atomic number.
He arranged the table by atomic number instead.
Realized that there were undiscovered elements

12. The Current Periodic Table
The horizontal rows are called periods and are labeled from 1 to 7.
Each period has a new electron energy level

13. Periods go across

14. The vertical columns are called groups are labeled from 1 to 18.
Each group has the same number of electrons in the outermost energy level. (valence electrons)

15. Summary of the Table’s arrangement
Elements are arranged by increasing atomic number
Elements in the same period have the same number of electron energy levels
Elements in the same group the same number of valence electrons
Valence electrons are the electrons found in the outermost energy level.

16. Valence electrons-How many electrons are in the outermost shell?Si Ge

17. Element Superhero Project

18. Learn about your element
It’s history
It’s physical and chemical properties
It’s periodic table location and family
Create a superhero for your element displaying its characteristics such as strengths and weaknesses, its hideouts, and super powers.

19. Families on the Periodic Table
Columns are also grouped into families.
Families may be one column, or several columns put together.
Families have names rather than numbers. (Just like your family has a common last name.)

20. Families of the Periodic Table

21. Families of Elements 1 Alkali Metals 2 Alkaline Earth Metals
3-12 Transition Metals
13 The Boron Family
14 The Carbon Group
15 The Nitrogen Group
16 The Oxygen Group
17 The Halogens
18 The Noble Gases
Lanthanide Series
Actinide Series

22. Transition Elements Groups 3-12 Transition Elements
All transition elements are metals.
Group 11 (The Coinage Metals)
The Lanthanides
The Actinides

23. Hydrogen Hydrogen belongs to a family of its own.
Hydrogen is a diatomic, reactive gas.
Hydrogen was involved in the explosion of the Hindenberg.
Hydrogen is promising as an alternative fuel source for automobiles

24. Alkali Metals
1st column on the periodic table (Group 1) not including hydrogen.
Very reactive metals, always combined with something else in nature (like in salt).
Soft enough to cut with a butter knife

25. Alkali Metals

26. Alkaline Earth Metals Second column on the periodic table. (Group 2)
Reactive metals that are always combined with nonmetals in nature.
Several of these elements are important mineral nutrients (such as Mg and Ca)

27. Transition Metals Elements in groups 3-12 Less reactive harder metals
Includes metals used in jewelry and construction.
Metals used “as metal.”

28. Boron Family Elements in group 13
Aluminum metal was once rare and expensive, not a “disposable metal.”

29. Carbon Family Elements in group 14
Contains elements important to life and computers.
Carbon is the basis for an entire branch of chemistry.
Silicon and Germanium are important semiconductors.

30. Nitrogen Family Elements in group 15
Nitrogen makes up over ¾ of the atmosphere.
Nitrogen and phosphorus are both important in living things.
Most of the world’s nitrogen is not available to living things.
The red stuff on the tip of matches is phosphorus.

31. Oxygen Family or Chalcogens
Elements in group 16
Oxygen is necessary for respiration.
Many things that stink, contain sulfur (rotten eggs, garlic, skunks,etc.)

32. Halogens Means salt former Elements in group 17
Very reactive, volatile, diatomic, nonmetals
Always found combined with other elements in nature .
Used as disinfectants and to strengthen teeth.

33. The Noble Gases

34. The Noble Gases Elements in group 18 VERY unreactive, monatomic gases
Used in lighted “neon” signs
Used in blimps to fix the Hindenberg problem.
Have a full valence shell.

36.
Meet the Elements

38. Families on the Periodic Table
Elements on the periodic table can be grouped into families bases on their chemical properties.
Each family has a specific name to differentiate it from the other families in the periodic table.
Elements in each family
react differently with
other elements.

39. Periods Each row is called a “period”
The elements in each period have the same number of shells
1st Period = 1 Shell
2nd Period = 2 Shells
3rd Period = 3 Shells
4th Period = 4 Shells

40. Groups Group 8 = 8 electrons Group 1 = 1 electron
Except for He, it has 2 electrons
Group 2 = 2 electrons
Each column is called a “group”
3, 4, 5, 6, 7
Each element in a group has the same number of electrons in their outer orbital, also known as “shells”.
The electrons in the outer shell are called “valence electrons”

43. Periodic table song
"Hunting the Elements" NOVA special
(2012) NOVA show Hunting The Elements
lecture series with Peter Wothers is really, really good: The Modern Alchemist: Air : Ri Channel  It covers something we all experience with every breat