Chapter 6 The Periodic Table and Periodic Law

Chapter 6 Standards CHEM.A.2.3.1 Explain how the periodicity of chemical properties led to the arrangement of elements on the periodic table. CHEM.A.2.3.2 Compare and/or predict the properties (e.g., electron affinity, ionization energy, chemical reactivity, electronegativity, atomic radius) of selected elements by using their locations on the periodic table and known trends.

Development of the Modern Periodic Table Section 6.1 Development of the Modern Periodic Table

Objectives Trace the development and Identify key features of the periodic table.

Key Terms Periodic law Group Period Representative elements Transition elements Metals Alkali metals Transition metals Inner transition metals Nonmetals Halogens Noble gases metalloid

History 1790s, French scientist Lavoisier 23 elements 1800s: electricity and spectrometer

John Newlands Patterns on the periodic table Law of octaves Elements on the eights had similarities

Meyer & Mendeleev 1869: connection between atomic mass and properties Mendeleev published first Left holes of undiscovered elements Predicted properties of undiscovered elements- Sc, Ga, Ge

Moseley Problems with Mendeleev Rows by increasing atomic mass Moseley used atomic number instead

The Periodic Law There is periodic repetition of chemical and physical properties when elements are arranged by increasing atomic number.

The Modern Periodic Table Horizontal rows- periods (7) Vertical columns- groups or families (18)

Groups 1,2 and 13-18= Representative Elements Groups 3-12= Transition Elements

Metals shiny, smooth solid room temperature good conductors of heat and electricity

Alkali Metals Group1 (excluding hydrogen) highly reactive

Alkaline Earth Metals Group 2 highly reactive (not as much as 1)

Group B Metals Transition metals elements contained in D block Inner transition metals the lanthanide (4f) and actinide (5f) series

Nonmetals Generally a gas or a brittle, dull solids Poor conductors

Nonmetal Families Halogens= group17 REALLY REACTIVE Noble Gases= group18 Unreactive/stable (all valence electrons are filled)

Metalloids Have characteristics of both metals and nonmetals B, Si, Ge, As, Sb, Te, At Separate metals on the left from nonmetals on the right

Homework Worksheet

Classification of the Elements Section 6.2 Classification of the Elements

Objectives Explain why elements in the same group have similar properties Identify the four blocks of the periodic table based on electron configuration

Valence Electrons The properties of elements in each group are similar because they have same number of valence electrons

Valence Electrons and Period Number Energy level of valence electrons = period on the table Ex: Lithium: period 2, valence electron in 2nd energy level (1s22s1)

Valence Electrons and Group Number Group number (1A-8A) = number of valence electrons

REVIEW 4 different energy sublevels s, p, d, and f S block= 1A and 2A holds max of 2 electrons P block= 3A through 8A max holds 6 electrons S block must fill before P block can fill Noble gases are stable because of filled S and P blocks

REVIEW D block = transition metals F block= inner transition metals max of 10 electrons F block= inner transition metals unpredictable manner of filling max of 14 electrons

Reactivity Trends Increases down the table for the metals Decreases down the table for the nonmetals                                                                                                                                         

Homework Worksheet