1. The Periodic Table

2. What is the Periodic Table? An arrangement of elements in columns, based on a set of properties that repeat from row to row Element-a substance that cannot be broken down into simpler substances

3. Why is the Periodic Table important? The periodic table is the most useful tool to a chemist. You get to use it on every test.

4. Pre-Periodic Table Chemistry … …was a mess!!! No organization of elements. Imagine going to a grocery store with no organization!! Difficult to find information. Chemistry didn’t make sense.

5. Dmitri Mendeleev: Father of the Table HOW HIS WORKED… Put elements in rows by increasing atomic weight. Put elements in columns by the way they reacted. SOME PROBLEMS… He left blank spaces for what he said were undiscovered elements. (Turned out he was right!) He broke the pattern of increasing atomic weight to keep similar reacting elements together.

6. The Current Periodic Table Mendeleev wasn’t too far off. Now the elements are put in rows by increasing ATOMIC NUMBER!! The horizontal rows are called periods and are labeled from 1 to 7. The vertical columns are called groups are labeled from 1 to 18 and can be grouped in A and B

8. Properties of Metals Metals are good conductors of heat and electricity. Metals are shiny. Metals are ductile (can be stretched into thin wires). Metals are malleable (can be pounded into thin sheets). A chemical property of metal is its reaction with water which results in corrosion.

9. Properties of Non-Metals Non-metals are poor conductors of heat and electricity. Non-metals are not ductile or malleable. Solid non-metals are brittle and break easily. They are dull. Many non-metals are gases. Sulfur

10. Properties of Metalloids Metalloids (metal-like) have properties of both metals and non-metals. They are solids that can be shiny or dull. They conduct heat and electricity better than non-metals but not as well as metals. They are ductile and malleable. Silicon

11. 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.)

12. Families Periods Elements in each family have similar but not identical properties. For example, lithium (Li), sodium (Na), potassium (K), and other members of family IA are all soft, white, shiny metals. All elements in a family have the same number of valence electrons. The elements in a period are not alike in properties. In fact, the properties change greatly across even given row. The first element in a period is always an extremely active solid. The last element in a period, is always an inactive gas.

14. Hydrogen Hydrogen belongs to a family of its own. Hydrogen is a diatomic, reactive gas. It has one proton and one electron in its one and only energy level. Hydrogen only needs 2 electrons to fill up its valence shell.

15. Hydrogen Hydrogen was involved in the explosion of the Hindenberg. Hydrogen is promising as an alternative fuel source for automobiles

16. Alkali Metals The alkali family is found in the first column of the periodic table. Atoms of the alkali metals have a single electron in their outermost level, in other words, 1 valence electron. They are shiny, have the consistency of clay, and are easily cut with a knife.

17. Alkali Metals They are the most reactive metals. They react violently with water. Alkali metals are never found as free elements in nature. They are always bonded with another element.

18. What does it mean to be reactive? Elements that are reactive bond easily with other elements to make compounds. Some elements are only found in nature bonded with other elements. What makes an element reactive? –An incomplete valence electron level. –All atoms (except hydrogen and helium) want to have 8 electrons in their very outermost energy level (This is called the octet rule.) –Atoms bond until this level is complete. Atoms with few valence electrons lose them during bonding. Atoms with 5, 6, or 7 valence electrons gain electrons during bonding.

19. Alkaline Earth Metals Second column on the periodic table. (Group 2) Reactive metals that are always combined with nonmetals in nature. They have two valence electrons. Alkaline earth metals include magnesium and calcium, among others.

20. Transition Metals Transition Elements include those elements in the B families (groups 3-12) They are good conductors of heat and electricity. Transition elements have 1 or 2 valence electrons, which they lose when they form bonds with other atoms. Some transition elements can lose electrons in their next-to-outermost level.

21. Transition Metals Less reactive, harder metals Includes metals used in jewelry and construction. The compounds of transition metals are usually brightly colored and are often used to color paints.

22. Boron Family The Boron Family is named after the first element in the family. Elements in group 13 Atoms in this family have 3 valence electrons. This family includes a metalloid (boron), and the rest are metals. This family includes the most abundant metal in the earth’s crust (aluminum).

23. Carbon Family Elements in group 14 Atoms of this family have 4 valence electrons. This family includes a non-metal (carbon), metalloids, and metals.

24. Carbon Family The element carbon is called the “basis of life.” There is an entire branch of chemistry devoted to carbon compounds called organic chemistry. Silicon and Germanium are important semiconductors.

25. Nitrogen Family Elements in group 15 The nitrogen family is named after the element that makes up 78% of our atmosphere. This family includes non-metals, metalloids, and metals. Atoms in the nitrogen family have 5 valence electrons. They tend to share electrons when they bond.

26. Nitrogen Family Other elements in this family are phosphorus, arsenic, antimony, and bismuth. 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.

27. Oxygen Family or Chalcogens Elements in group 16 Atoms of this family have 6 valence electrons. Most elements in this family share electrons when forming compounds. Oxygen is the most abundant element in the earth’s crust. It is extremely active and combines with almost all elements.

28. Oxygen Family or Chalcogens Oxygen is necessary for respiration. Many things that stink, contain sulfur (rotten eggs, garlic, skunks,etc.)

29. Halogen Family Elements in group 17 The elements in this family are fluorine, chlorine, bromine, iodine, and astatine. Halogens have 7 valence electrons, which explains why they are the most active non- metals.. Halogen atoms only need to gain 1 electron to fill their outermost energy level. They react with alkali metals to form salts.

30. Halogens Always found combined with other element in nature. Used as disinfectants and to strengthen teeth.

31. Noble Gases Elements in group 18 Noble Gases are colorless gases that are extremely un-reactive. One important property of the noble gases is their inactivity. They are inactive because their outermost energy level is full. Because they do not readily combine with other elements to form compounds, the noble gases are called inert. All the noble gases are found in small amounts in the earth's atmosphere.

32. The Noble Gases The family of noble gases includes helium, neon, argon, krypton, xenon, and radon. Used in lighted “neon” signs Used in blimps to fix the Hindenberg problem.

33. Rare Earth Elements The thirty rare earth elements are composed of the lanthanide and actinide series. One element of the lanthanide series and most of the elements in the actinide series are called trans-uranium, which means synthetic or man-made.