1. Physical Science 513 Unit 3 3.4 – The Periodic Table

2. Lesson Objectives 12. 12. Describe how the periodic table is arranged 13. 13. Describe the periodic trends of atom size, ionization numbers, and reactivity within the groups and periods of the table 14. 14. Identify common features of metals, non- metals, and metalloids

3. Periodic Table 7 horizontal rows - periods 18 vertical columns - groups (or families) Groups – –Have numbers (1-18) – –Most also have common names   Group 1 - Alkali metals   Groups 3-12 - Transition metals   Group 18 - Noble Gases

4. Periodic Trends Periodic Law: When elements are arranged in order of increasing atomic number, their physical and chemical properties show a periodic (repeating) pattern Elements across a period change in predictable ways Elements within the same group have similar properties

5. Periodic Trends 1. 1. Atomic size Decreases across a period – –Addition of protons increases the attraction between the nucleus and electrons Increases down a group – –Addition of an electron shell with each row

6. Periodic Trends 2. 2. Ionization numbers How many electrons are lost, gained or shared when bonding occurs The pattern of ionization numbers for Groups 1,2,13-18 are: +1, +2, +3, +/-4, -3, -2, -1, 0.

7. Periodic Trends 3. 3. Reactivity How readily elements will form compounds The first element in a period is always a very active solid; the last element is always a very inactive gas Reactivity increases as you go down a group

8. Periodic Table There are three types of elements: Metals, Nonmetals, and Metalloids http://faculty.xavierhs.org/chiafuliom/phychem/periodic_table_quest/metalsetc.jpghttp://faculty.xavierhs.org/chiafuliom/phychem/periodic_table_quest/metalsetc.jpg; 11/20/12

9. Periodic Table Properties of metals include: Properties of nonmetals include: Metalloids have properties of both metals and nonmetals ● shiny, opaque, good conductors, malleable, ductile, mostly solids at room temperature ● under normal conditions, hydrogen behaves as a nonmetal ● many are transparent, poor conductors, mostly gases at room temp ● solid nonmetals are brittle, not malleable or ductile