Mendeleev’s Periodic Table

1. Mendeleev’s Periodic Table Dmitri Mendeleev

2. Modern Russian Table

3. Stowe Periodic Table

4. A Spiral Periodic Table

5. “Mayan” Periodic Table

6. Period The Periodic Table Group or Family Group or family Period

7. Properties of Metals • Metals are good conductors of heat and electricity • Metals are malleable • Metals are ductile • Metals have high tensile strength • Metals have luster

8. Examples of Metals Potassium, K reacts with water and must be stored in kerosene Copper, Cu, is a relatively soft metal, and a very good electrical conductor. Zinc, Zn, is more stable than potassium Mercury, Hg, is the only metal that exists as a liquid at room temperature

9. Propertiesof Nonmetals Carbon, the graphite in “pencil lead” is a great example of a nonmetallic element. • Nonmetals are poor conductors of heat and • electricity • Nonmetals tend to be brittle • Many nonmetals are gases at room temperature

10. Examples of Nonmetals Microspheres of phosphorus, P, a reactive nonmetal Sulfur, S, was once known as “brimstone” Graphite is not the only pure form of carbon, C. Diamond is also carbon; the color comes from impurities caught within the crystal structure

11. Properties of Metalloids Metalloids straddle the border between metals and nonmetals on the periodic table. • They have properties of both metals and nonmetals. • Metalloids are more brittle than metals, less brittle than most nonmetallic solids • Metalloids are semiconductors of electricity • Some metalloids possess metallic luster

12. Silicon, Si – A Metalloid • Silicon has metallic luster • Silicon is brittle like a nonmetal • Silicon is a semiconductor of electricity Other metalloids include: • Boron, B • Germanium, Ge • Arsenic, As • Antimony, Sb • Tellurium, Te

13. The Properties of a Group: the Alkali Metals • Easily lose valence electron (Reducing agents) +1 • Soft enough to cut with a knife • React violently with water • Stored in Oil • React with halogens to form salts

14. The Properties of a Group IIA: Alkaline Earth Metals 2 e- in outer shell Will lose 2 e- : +2

15. Group IIIA: The Boron Family 3 e- in the outer shell B- metalloid, All other elements are metals, will form then 3+ ions Al- 3rd most abundant element in earth’s crust, very strong in alloys, doesn’t corrode easily

16. Group IVA: Carbon Family 4 e- in outer shell Si: 2nd most abundant in Earth’s crust SiO2 is in sand, semi conductor, silica=glass Ge: electronic devices Sn: coats steel for “tin cans” Pb: In batteries and computer, used to be in paint and gas

17. Group VA: Nitrogen Family 5 e- in outer shell N & P: Nonmetals As & Sb are metalloids Bi: Metal N: 79% of earth’s atmosphere, colorless, odorless and diatomic (N2 ) P: in your bones; in fertilizers, detergents, soft drinks

18. Group VIA: Oxygen Family 6 e- in outer (normally will gain 2e-; 2- charge then) O, S, Se: Nonmetals Te: metalloid Po: metal (metalloid) O: most abundant element on earth, colorless, odorless, diatomic (O2); extremely reactive, O3 S: unpleasant odor; added to natural gas to detect leaks; skunks, rotten eggs

19. The Properties of Group VIIA: The Halogens Contain 7 e- in outer shell Easily gain valence electron (Oxidizing agents) -1 Can be prepared from their “salt” NaCl  Cl2 NaF  F2  KBr  Br2

20. Group VIIIA: Noble Gases Inert Elements Filled Outer Energy (filled s and p’s) 8e- in outer shell; chemically inactive

22. Determination of Atomic Radius: Half of the distance between nucli in covalently bonded diatomic molecule "covalent atomic radii" Periodic Trends in Atomic Radius • Radius decreases across a period Increased effective nuclear charge due to decreased shielding • Radius increases down a group Addition of principal quantum levels

23. Table of Atomic Radii

24. Ionization Energy - the energy required to remove an electron from an atom • Increases for successive electrons taken from • the same atom • Tends to increase across a period Electrons in the same quantum level do not shield as effectively as electrons in inner levels Irregularities at half filled and filled sublevels due to extra repulsion of electrons paired in orbitals, making them easier to remove • Tends to decrease down a group Outer electrons are farther from the nucleus

25. Table of 1st Ionization Energies

26. Ionization of Magnesium Mg + 738 kJ  Mg+ + e- Mg+ + 1451 kJ  Mg2+ + e- Mg2+ + 7733 kJ  Mg3+ + e-

27. Another Way to Look at Ionization Energy

28. Electronegativity The ability of an atom in a molecule to attract shared electrons to itself. Linus Pauling 1901 - 1994

29. Table of Electronegativities

30. Electronegativity A measure of the ability of an atom in a chemical compound to attract electrons • Electronegativities tend to increase across • a period • Electronegativities tend to decrease down a • group or remain the same

31. Periodic Table of Electronegativities

32. Ionic Radii • Positively charged ions formed when • an atom of a metal loses one or • more electrons Cations • Smaller than the corresponding • atom • Negatively charged ions formed • when nonmetallic atoms gain one • or more electrons Anions • Larger than the corresponding • atom

33. Table of Ion Sizes

34. Summation of Periodic Trends