Properties of the Periodic Table

1. Properties of the Periodic Table

2. The Periodic Table Vertical columns are called Groups Groups are numbered from 1 to 18

3. The Periodic Table • Valence Electrons are electrons located on the outermost energy level. • Each element in a group has the same number of valence electrons

4. Each row is called a period Each period starts with an atom with one electron in the outer energy level and ends with an atom that has a fullouter energy level The Periodic Table

5. The Periodic Table • The Periodic Table has 3 main sections of elements with similar properties: • Metals • Nonmetals • Metalloids

6. Specifics on Groups of the Periodic Table

7. Metals • Properties of metals include: • Conduct heat & electricity • Solid at room temperature - all except Mercury (Hg)

8. Metals • Properties of metals include: • Reflective, malleable, ductile • Located on the left sideof the Periodic Table

9. Alkali Metals

10. Alkali Metals • The first column of the periodic table • Forms +1 Ions by losing the 1 valence electron • The most reactivemetals on the periodic table • Sodium explodes when exposed to the air http://video.google.com/videoplay?docid=-2134266654801392897#

11. Alkaline Earth Metals

12. Alkaline Earth Metals • Second group on the periodic table • Also very reactive, but not as muchas the alkali metals • Forms +2 Ions by losing the 2 valence electrons.

13. Transition Elements • Groups 3-12 are the more stable Transition Elements • They usually exist uncombined with other elements because they are not as reactive

14. Transition Elements • Usually form multiple positiveions. i.e. Copper forms +1 or +2 depending on the compound.

15. Inner Transition Elements The disconnected rows underneath the rest of the table They fit between groups 3 & 4 in periods 6 & 7

16. Inner Transition Elements • The first row contains theLanthanides, starting with Lanthanum • The second row contains the Actinides, starting with Actinium • They are very unstable because of the high number of neutrons versus protons

17. Nonmetals

18. Nonmetals Properties of nonmetals: Usually gases or brittle solidsat room temperature Exception is Bromine (liquid)

19. Nonmetals Properties of nonmetals: Not malleable or ductile Not usually conductive or reflective Form negative ions by gaining valence electrons.

20. Noble Gases

21. Noble Gases They are in group 18 of the periodic table They are the most stableof all elements. They don’t reactwith other elements under normal conditions

22. Halogens

23. Halogens Group 17 on the periodic table They are not usually found in nature alonebut as salts(Combined with a metal) Some are called diatomic molecules (exist in a molecule of 2 atoms)

24. Halogens Readily gain 1 valence electron to form a -1 ion. Halogens are very reactive The most reactivenon-metals!

25. Diatomic Molecules • Some nonmetals are called diatomic because they exist as a molecule of two atoms joined together • This means that Natural Oxygen exists as O2

26. Metalloids

27. Metalloids Elements that have properties of metals and nonmetals Groups 13, 14, 15, 16, and 17 contain metalloids

28. Metalloids • The metalloids are: • Boron • Silicon • Germanium • Arsenic • Antimony • Tellurium • Polonium

29. Metalloids • Have a combination of the properties of metals and non-metals • In a zig-zag from top of Boron to the bottom of Polonium

30. Periodic Trends

31. Periodic Trends • The periodic table is organized in such a way that repeatingpatterns, or trends, can be seen.

32. Periodic Trends • There are three main trends • Atomic mass • Atomic radius • Reactivity

33. Atomic Mass Trend • As you go from left to right, mass increases • As you go from top to bottom, mass increases

34. Atomic Mass Trend • Why? • As we go left to right or top to bottom, there is an increase in amount of matter • ProtonsandNeutronsincrease

35. Which has more mass? F or O N or As Na or K Sr or Li H or Xe

36. Atomic Radius (Size) Trend • Atomic Radius is the distance from the center of the nucleus to the outside of the electron cloud • Measure in Angstroms (Ǻ)

37. Atomic Radius (Size) Trend • As you go from left to right, radius decreases • As you go from top to bottom, radius increases

38. Atomic Radius (Size) Trend • Why? • As we go left to right , the nucleus pulls the atom tighter. • Top to bottom, there are more energy levelsbeing added.

39. Which has a bigger radius? F or O N or As Na or K Sr or Li H or Xe

40. Reactivity Trend • Tells how reactive elements are, or how strongly they will interact with other elements • As you go from left to right, reactivity of metals decreases, and then the reactivity of nonmetals increases (but stops at the halogens)

41. Reactivity Trend • As you go from top to bottom, reactivity increases on the left and decreases on the right • Why? • Metals at the bottom lose electronsand nonmetals at the top gain electrons. • Therefore the corners are the most reactive.

43. Reactivity Trend • Most Reactive Metal and Nonmetal Start with “F” • Can you guess what they are? Remember the Alkali metal reactivity video… http://video.google.com/videoplay?docid=-2134266654801392897#

44. Bohr Models • One way to see the trend of Valence Electrons is to draw a Bohr model. • Remember Bohr placed electrons in specific orbits, or energy levels. 1st = 2 electrons 2nd =8electrons 3rd = 18 electrons 4th = 32 electrons

45. Bohr Models • Lets Draw the Bohr models for some of the elements in group 1 • What do you notice?

46. Lewis Dot Diagrams • Soon we will learn that although as many as 32 electrons can sit on an outer energy level, we are only concerned about the outermost 8, which are the valence electrons. • This is what we call an Octet. (8 Electrons)

47. Lewis Dot Diagrams • We show how an element’s octet is filled using a Lewis Dot structure. • Let’s draw the Lewis Dot Diagrams for the same atoms and some new ones.

48. Valence Electrons • Valence Electrons become VERY important in our next unit!!!

49. Lewis Dot Diagrams