Notes: 6.1 & 6.2 OBJECTIVES: Students will be able to (SWBAT) 1. Explain how the periodic table was developed 2. Identify key features of the periodic table 3. Explainwhy elements in the same group have similar properties 7lecture Q s (and 8Reading Q s) 5-sentence summary
Development of the Modern Periodic Table (Chapter 6, Section 1)
The History of the Periodic Table Pages 151 153 LAVOISIER NEWLANDS MEYER MENDELEEV MOSELEY WHEN (YEAR) WHAT (DISCOVERIES)
The History of the Periodic Table Pages 151 153 LAVOISIER NEWLANDS MEYER MENDELEEV MOSELEY WHEN (YEAR) 1790 s 1864 1869 1869 1913 WHAT (DISCOVERIES)
The History of the Periodic Table Pages 151 153 LAVOISIER NEWLANDS MEYER MENDELEEV MOSELEY WHEN (YEAR) 1790 s 1864 1869 1869 1913 WHAT (DISCOVERIES) Compiled a list of 23 known elements Law of Octaves repeating pattern of 8 elements by atomic mass Made connection between atomic mass and properties of elements 1 st credited with creating a useful periodic table; predicted yet to be discovered elements Organized elements by atomic number PERIODIC LAW
The History History of the Periodic Table Lavoisier 1700 s; listed 23 known elements at the time Newlands created the Law of Octaves (or eight) Organized elements by atomic mass and saw that chemical properties repeat every 8 elements (repeating pattern is called periodic) Meyer, Mendeleev and Moseley Modern Periodic Table Mendeleev (father of the first Modern Periodic Table) arranged by increasing atomic mass and in columns by similar chemical properties Moseley arranged table by increasing atomic number (number of protons) which corrected some of the errors in Mendeleev s table
Repeating (periodic) pattern of 8
The problem
and later still
The Modern Periodic Table Periodic Law: repetition of chemical and physical properties of elements arranged by increasing atomic number Arrangement and Organization Refer to your periodic table handout
The Modern Periodic Table A groups REPRESENTATIVE ELEMENTS B groups TRANSITION ELEMENTS NONMETALS METALS staircase On staircase METALLOIDS or SEMIMETALS
Pages 156-157 Groups (columns) Periods (rows) Element Atomic number Symbol Atomic Mass METALS State of matter NON- METALS METALLOIDS
Types of Metals and Nonmetals Most elements are metals Alkali metals (group 1A, except Hydrogen) Alkaline earth metals (group 2A) Transition metals (all group B s) Inner Transition metals (f-block elements) Halogens (group 7A) Noble gases (group 8A)
Alkali metals Alkaline Earth metals Halogens Noble gases Transition metals Inner Transition metals
Inner Transition Metals (f-block) #58 (cerium) starts after Lanthanum (La; #57) From Ceto Lu Called the LANTHANIDE SERIES #90 (thorium) starts after Actinium (Ac; #89) From Thto Lr Called the ACTINIDE SERIES
Classification of the Elements (Chapter 6, Section 2)
Organization of Elements by Electron Configuration Similar chemical properties are due to same number of valence e - Same group same # of valence e - similar chemical and physical properties Valence electrons by group number (only for representative or A group elements) Example: Group 1A (alkali metals) e - configends in s 1 1 valence e - Valence electrons by period number Example: Period 3 elements have valence electrons in the highest energy level level 3
Valence electron configurations s 2 p 5 are all the elements in group 5A because they all end with electron configurations of s 2 p 5 this represents the valenceor outer electron configuration F 1s 2 2s 2 2p 5 Cl 1s 2 2s 2 2p 6 3s 2 3p 5 Br 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 5 I 1s 2 2s 2 2p 6 3s 2 3p 6 4s 2 3d 10 4p 6 5s 2 4d 10 5p 5 All of the above elements are in group 7A and have 7 valence e - halogens Period 2 highest level is 2 Period 3 highest level is 3 Period 4 highest level is 4 Period 5 highest level is 5
Elements in the same group have similar Lewis Dot Structures
The s, p, d and f Block Elements The s, p, d and f Block Elements s-block (groups 1A and 2A) alkali & alkaline earth p-block (groups 3A -8A) mostly nonmetals, halogens and noble gases d-block (the B groups) transition metals f-block inner transition metals
Tell me the GROUP, PERIOD and BLOCK [Ne]3s 2 3p 5 GROUP: 7A PERIOD: 3 BLOCK: p
1) s 2 List all the elements with the following valence electron configurations. What are the group numbers? What type of element are they? Be, Mg, Ca, Sr, Ba, Ra Group 2A Alkaline earth metals X 2) s 2 d 1 Sc, Y, La, Ac Group 3B Transition metals 3) s 2 p 6 Ne, Ar, Kr, Xe, Rn Group 8A Noble Gases X