The Periodic Table

1. Unit 2 The Periodic Table

2. Is an organized chart of all the elements known to science. * most elements occur naturally [91] * some have been created in labs [18]

3. First Periodic Table was created in the late 1800’s by a Russian chemists named Dmitri Mendeleev.

4. It is called a periodictable because of the repeating pattern of elements. * a calendar is an example of a periodic table of days

5. Because of this pattern, Mendeleev predicted the discovery of 3 new elements. * he predicted their approximate mass, properties, chemical activity based on their location * he was right

6. Mendeleev put his table in order by increasing atomicmass. * today’s table is in order by increasingatomicnumbers

7. The Format of the Periodic Table • Period = a row across the table * it shows the repeating pattern * each period represents an energy level * 7 periods on the table

8. 1 2 3 4 5 6 7 6 7

9. The Format of the Periodic Table • Family (Group) = a column up and down on the table * they have similar properties * they will react the same way * 18 families (groups) on the table

10. 1 18 2 13 14 15 16 17 3 4 5 6 7 8 9 10 11 12

11. Some Families have names given to them. • Family 1 = Alkali Metals • Family 2 = Alkaline Earth Metals • Families 3 – 12 = Transitional Metals (a.k.a.: transitional elements) • Family 17 = Halogens • Family 18 = Noble Gases

12. 3 Categories of Elements • Metals • Non-Metals • Metalloids

13. The Format of the Periodic Table • Metals are located on the left side. * solids at room temperature * mostly shiny * good conductors * malleable and ductile

15. The Format of the Periodic Table • What makes a METAL a METAL? * its properties

16. The Format of the Periodic Table • Non-Metals are located on the far right side. * mostly gases at room temperature * some are brittle solids * do not conduct electricity * not malleable or ductile

18. The Format of the Periodic Table • What makes aNON-METALaNON-METAL? * its properties

19. The Format of the Periodic Table • Metalloids are located on the Stair-Step Line. * have properties of metals and non-metals * will react differently based on the situation

21. The Format of the Periodic Table • What makes a METALLOID a METALLOID? * its properties

22. Color code your Periodic Table.

24. Informationfoundinthe PeriodicTable • Element name • Element symbol • Atomic number(# of protons) also electrons • Atomic mass • State of matter • Family Number • Period (# of energy levels)

25. 15 Family # Nitrogen Name Atomic # protons & electrons 7 State of Matter N Symbol Atomic Mass 14.007 Period is found by following the row to the left.

26. Informationnotfoundin thePeriodicTable • Mass number * the table would beTOOlarge * each isotope would need its own box

27. The Periodic Table has hidden information about each element. * you just have to know how to read what it tells you

28. An elements reactivity is based on the number of electrons in its outer energy (valence) level. * to be stable they need 8 electrons in their O.E.L.

29. How to tell how many electrons are in the outer energy level. • Look at the Family (Group) Number / / / / 01 = 1 02 = 2 13 = 3 14 = 4 15 = 5 16 = 6 17 = 7 18 = 8 Does not hold true for families 3 - 12

30. Dot Diagram • Uses the element’s symbol and a dot to represent EACH electron in its outerenergylevel.

31. Examples of Dot Diagrams Li Ca Aℓ Br Kr

32. Family (Group) 18 = The Noble Gases • Rarely will react with other elements. • Can combine under extreme circumstances.

33. Synthetic Elements • Created in a laboratory; are not naturally occurring. * created by colliding elements and other particles together and forcing them to stick * most are radioactive

34. Radioactive Element • An unstable element whose nucleus breaks down and gives off particles, radiation and energy.

35. The End