What are Elements?

1. What are Elements? • 7-5.2 Classify matter as element, compound, or mixture on the basis or its composition.

2. Engage: The Chemical Elements Song (1:24) • http://www.youtube.com/watch?v=K8eT-k4f7_8

3. Elements • Definition: Pure substance made of one kind of atom • Cannot be broken down into another substance. • Each element is known for its own individual properties

4. Elements chemically combine to produce compounds. A. Atoms of an element B. Molecule of an element C. Molecules of a compound D. Mixture of 2 elements + a compound

5. Elements • There are over 100 elements organized in the periodic table of elements.

6. Elements • Each element has its own atomic number which is always a whole number.

7. Each element has its own CHEMICAL SYMBOL, a symbolic representation of the element. • Elements are arranged on the Periodic Table of Elements numerically by ATOMIC NUMBER.

8. CFU: Find the Symbol and Atomic #:

11. Element Name Atomic Number Element Symbol Atomic Mass

12. CFU: Element “?” has the number 10.811 by it. That must be it’s ___. • atomic mass • atomic number • atomic size • atomic weight

13. CFU Review: What are the two kinds of Pure Substances? • Elements • Compounds

14. CFU: Element “X” is chemically combined with Element “Z” to make “XZ”. “XZ” is considered to be ___. • an element • a compound • a heterogeneous mixture • a homogeneous mixture

15. The Periodic Table of Elements 7-5.4 Use the periodic table to identify the basic organization of elements and groups of elements (including metals, nonmetals, and families).

16. Engage Activity • Scavenger Hunt-Element Search: • students try to find as many words as they can from different elemental symbols being combined: • BaKEr • Note to Teacher: • PULL UP ActiveInspire Periodic Table

17. Why is the Periodic Table important to me? • The periodic table is the most useful tool to a chemist. • You get to use it on every chemistry test. • It organizes lots of information about all the known elements.

18. Pre-Periodic Table Chemistry … • …was a mess!!! • Elements were NOT organized. • Imagine going to a grocery store with no organization!! • It was difficult to find information. • Chemistry didn’t make sense.

19. Dmitri Mendeleev: Father of the Table

20. 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.

22. Solving the puzzle of the periodic table – Eric Rosado • http://www.youtube.com/watch?v=O-48znAg7VE • 4:19

23. The Periodic Table of Elements • Mendeleev wasn’t too far off. • Elements are arranged numerically by ATOMIC NUMBER.

24. Groups & Families • Columns (up and down) are groupedinto families. • Families are also called groups. • Families may be one column, or several columns put together. • Families have namesrather than numbers. (Just like families share a common last name.)

25. Families • Elements in the same family have similar chemical and physicalproperties! (react similarly to other substances) • (Mendeleev did that on purpose.)

26. Family Names

27. *Remember…. Column • Columns are grouped into families. Family

28. *Remember…. Column Family

29. Periods • A horizontal row (left to right) is called a period. Periods

30. Periodic Table of Elements • There is a zig-zag line that divides the metals from the non-metals. Zig-zag line

31. Metals are found on the left side of the zig-zag line. • Examples: Sodium, Calcium, Iron, and Aluminum • Non-metals are found on the right side of the zig-zag line. • Examples: Chlorine, Oxygen, Sulfur, and Iodine

32. CFU: Families are organized in the periodic table by ____. • left to right rows • left to right columns • up and down columns • up and down rows

33. CFU: Find another element in the same period as Helium. • Hydrogen (H)

34. CFU: Will Helium react more like Neon or Hydrogen? Why • More like Neon b/c they are in the same family! • Elements in the same family/group react to other substances similarly.

35. CFU: What is the purpose of the zig-zag line? • To separate Metals from Non-Metals

36. CFU: Is Potassium (K, #19) a metal, non-metal, or metalloid? How do you know? • Metal (left side of zig-zag line)

37. Outline each family/group with one color.

38. Outline each period with a different color.

39. Darkly separate the metals (left side) from the non-metals (right side) with a dark ZIG-ZAG line. Color the metal side with one color and non-metals with another color. (Do not use colors from above.)