1. TOPIC: Metals vs Nonmetals

2. Classifying the Elements metals 2/3 (75%) of elements are metals non-metalsmetalloids Remaining elements: non-metals & metalloids (semi-metals) Metalloids: – some properties of metals & some properties of nonmetals Staircase: Staircase: – dividing line between metals & nonmetals – elements to left are metals (except H) – elements to right are non-metals

4. Most elements are solid at room temperature Some nonmetals are gases –All the noble gases, of course –Some diatomics (H 2 N 2 O 2 F 2 Cl 2 ) There are only 2 Liquids at STP (room temp) –Br 2 (non-metal) and Hg (metal)

5. Properties of Metals Malleable – flattened into sheets Ductile – drawn into wires & tubes have Luster Good Conductors of heat & electricity Solid at room temperature (except Hg) “Metals are losers”Metals lose electrons & form positive ions “Metals are losers” Most reactive metal is Fr Most reactive family is Alkali Metals

6. So…metals don’t want electrons, they want to get rid of them

7. Metals also have… Low electronegativity (low attraction for electrons) Low ionization energy (doesn’t take a lot of energy to remove an electron)

8. Decreased Electronegativity Decreased Ionization energy

9. Properties of Nonmetals generally gases or solids (except Br 2 ) solids are Brittle solids are Dull poor conductors of heat & electricity “Nonmetals are winners”Nonmetals gain electrons & form negative ions “Nonmetals are winners” Most reactive nonmetal is FMost reactive nonmetal is F –Properties: OPPOSITE of metals

10. So…nonmetals love electrons, they want to take electrons

11. Nonmetals also have… high electronegativity (high attraction for electrons) high ionization energy (takes a lot of energy to remove an electron)

12. Increased Electronegativity Increased Ionization energy

13. Properties of Metalloids 7 metalloids: –5 on right of staircase: B,Si,As,Te,At –2 on left of staircase: Ge,Sb Each metalloid has some metallic and some nonmetallic properties –Example:Si shiny like metal but brittle like nonmetal Metalloids are elements touching the stairs (except Al) and have some properties of metals and some of nonmetals

14. Size of the Atom (Atomic Radius)

15. previousprevious | index | nextindexnext Li: Group 1 Period 2 Cs: Group 1 Period 6 Cs has more energy levels, so it’s bigger

16. Atomic Radius Gets Bigger

17. previousprevious | index | nextindexnext How about as you go across?!

18. as go across row size tends to decrease a bit because of greater PPP “proton pulling power” previousprevious | index | nextindexnext

19. Atomic Radius Gets Smaller