Unit 4 The Periodic Table

1. Unit 4The Periodic Table Chemistry I Mr. Patel SWHS

2. Topic Outline • Continue Learning Major Ions • Organization of the Periodic Table (6.1) • Classification of Elements (6.1) • Tour of the Periodic Table (6.2) • Periodic Trends (6.3)

3. Organizing the PT • Properties of elements are used to sort them • Mendeleev – 1st periodic table • Arranged elements based on atomic mass • Made predictions of new elements

5. Organizing the PT • Modern periodic table arranges elements based on atomic number • Periodic Law: repetition of physical and chemical properties

6. Metals • Most elements • Good conductors, high luster, ductile, malleable • Most are solid (except Hg) • Found left of stair-stepline

8. Nonmetals • Contains the gaseous elements • Mostly gas, few solids at room temp • Poor conductors • Brittle • Found to right ofstair-step line

10. Metalloids/Semimetals • Properties of metals and nonmetals • Based on physical conditions • Found above andbelow stair-step line

12. Periodic Table • Each block gives information about the element • Groups – columns • Periods – rows • Representative Elements – Groups 1A to 7A

13. Groups 63 Eu 152.0 Atomic Number Element symbol Groups Weighted average atomic mass Groups Periods Periods

14. Group 1A • Called the Alkali Metals • Elements: Li, Na, K, Rb, Cs,Fr (largest atom) • Very reactive with air and water • Form Bases (alkali)

15. Group 2A • Called the Alkaline-Earth Metals • Elements: Be, Mg, Ca, Sr (pic), Ba, Ra • Abundant in Earth Crust • Reactive with water - bases

16. Group 7A • Called Halogens • Elements: F, Cl, Br, I, At • Form salts

17. Group 8A • Called Noble Gases • Elements: He, Ne, Ar, Kr (pic), Xe, Rn • Full electron shell • Not Reactive • Gases

18. The Middle Ones • Elements between 2A and 3A • Transition metals – colors • Inner Transition metals at bottom of Periodic Table – Synthetic /Radioactive

19. The Periodic Table of Elements IA IIA IIIA IVA VA VIA VIIA VIIIA 1 Groups 2 3 IIIB IVB VB VIB VIIB VIIIB IB IIB 4 Periods 5 Transition metals 6 7 Halogens Noble gases Alkali metals Alkaline earth metals Lanthanoids Actinoids Inner Transition metals

20. Periodic Trends • Based on the organization of PT, trends in atomic parameters exist • Atomic Size • Ionization Energy • Electronegativity

21. Atomic Size • Atomic Radius – one half the distance between two nuclei when joined (same element)

22. Atomic Size Trend

23. Atomic Size • Atomic size: • Increases down a column • Decreases across a period Increasing Atomic Size Increasing Atomic Size

24. Ionization Energy • Ionization Energy (IE) – energy required to remove an electron from an atom

25. First Ionization Energy Trend

26. First Ionization Energy • Ionization Energy: • Decreases down a column • Increases across a period Increasing Ionization Energy Increasing IE

27. Electronegativity • Electronegativity – ability of an atom to attract/pull electrons

28. Electronegativity Trend

29. Electronegativity • Electronegativity: • Decreases down a column • Increases across a period Increasing Electronegativity Increasing EN

30. Trend Summary Atomic Size Electronegativity Ionization Energy

31. Which is the larger atom? • Be or F • Ca or Ba • Rb or Cl • Largest atom? • Be • Ba • Rb • Fr

32. Which has higher IE? • Be or F • Ca or Ba • Rb or Cl • F • Ca • Cl

33. Which has higher Electronegativity? • Be or F • Ca or Ba • Rb or Cl • Highest EN? • F • Ca • Cl • F