The Periodic Table

1. The Periodic Table And it’s trends

2. Mendeleev’s Periodic Table Dmitri Mendeleev

3. Modern Russian Table

4. Stowe Periodic Table

5. A Spiral Periodic Table

6. “Mayan” Periodic Table

7. The Periodic Table Period Group or Family

8. The Properties of a Group: the Alkali Metals • Easily lose valence electron • (Reducing agents) • React violently with water • Large hydration energy • React with halogens to form • salts

9. 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

10. 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

11. 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

12. 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

13. 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

14. 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

15. 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

16. Table of Atomic Radii

17. 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 Cations want to lose electrons, but anions do not. • Tends to decrease down a group Outer electrons are farther from the nucleus

18. One Way to Look at Ionization Energy

19. Electronegativity A measure of the ability of an atom in a chemical compound to attract electrons • Electronegativities tend to increase across • a period • - Cations don’t want elections, anions do. • Electronegativities tend to decrease down a • group or remain the same • - Electrons are further away from the • nucleus.

20. Periodic Table of Electronegativities

21. 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

22. Table of Ion Sizes