1. 4.2 The Periodic Table

2. Rules of the Periodic Table After organizing the Bohr model cards, write 4 rules that govern their organization.

3. Dmitri Mendeleev Russian scientist that first arranged the elements into rows and columns with similar properties in 1869.

4. ELEMENTS - Review Are made up of all the same atoms Identified by it’s atomic # (# of protons) Arrangement of valence electrons determines the elements properties such as conductivity and reactivity. The 1 st letter in chemical symbol is always capitalized. If there is a 2 nd letter, it is always lowercase. 13 Al 26.982 Aluminum

5. Columns on the PT Vertical Columns of the periodic table are called Groups or Families. Elements in groups have the same number of valence electrons and similar properties. They share characteristics with each other, just like human families do! Mark the Families on the PT. Which Group is most reactive? Color it red. Which Group is least reactive? Color it green.

7. Rows on the PT Horizontal rows on the periodic table are called Periods. Rows of the periodic table have elements with the same number of energy levels. Mark the Periods on the PT.

9. Groups vs. Periods Go up and down like a family tree Related/similar chemical properties Tells us the number of valence electrons Left to right (rows) Tells us the number of energy rings/levels

10. What is a Chemical Property? -A property or behavior of a substance when it undergoes a chemical change or reaction (it becomes a new substance.) Example: Metal oxidizes and becomes rust.

11. What is a Physical Property? A characteristic that can be observed or measured without changing the identity (composition) of the substance.

12. Examples of Physical Properties Ductility: a physical property of matter that describes its ability to be pulled into a wire

13. Examples of Physical Properties Malleability: a physical property of matter that describes the ability to be pounded into thin sheets Ex: pounding the coke can into a thin sheet of metal What does brittle mean?

14. Examples of Physical Properties Conductivity (being a conductor): a physical property of matter that describes the ability of a substance that transfers energy quickly. Ex: metal pans are good conductors of heat What is an example of a non-conductor?

15. Examples of Physical Properties Luster: a physical property of matter that describes the way light is reflected Ex: shiny rocks or metal Opposite of shiny is dull

16. Parts of the PT & characteristics The PT is broken into 3 main categories: – Metals – Nonmetals – Metalloids

17. Metals Metals are located to the LEFT of the zigzag line.

19. Metals Metals are: – Malleable: hammered into sheets – Ductile: stretched into wire – Have Luster: shiny – Good conductors of heat and electricity – Most are magnetic – Solid at room temperature

20. Nonmetals Nonmetals are located to the RIGHT of the zigzag line. (Exception: Hydrogen)

22. Nonmetals Nonmetals are: – Brittle: break easily – Dull: not shiny – Poor conductors of heat and electricity

23. Metalloids Metalloids are located along the borders of the zigzag line. (Exception: Aluminum)

25. Metalloids Metalloids have properties similar to both metals and nonmetals. – Semi-conductors (What does this mean?) – May be dull or shiny – May be brittle or malleable

26. Practice Understanding Valence Electrons w/s

27. Practice Unknown elements/PT w/s