1.1 Atoms, Elements and the Periodic Table

The Periodic Table and the Elements What is the periodic table ? What information is obtained from the table ? How can elemental properties be predicted base on the PT ?

Dmitri Mendeleev (1869) In 1869 Mendeleev and Lothar Meyer (Germany) published nearly identical classification schemes for elements known to date. The periodic table is base on the similarity of properties and reactivities exhibited by certain elements. Later, Henri Moseley ( England,1887-1915) established that each elements has a unique atomic number, which is how the current periodic table is organized. http://www.chem.msu.su/eng/misc/mendeleev/welcome.html

The periodic table is the most important tool in the chemist’s toolbox!

The Periodic Table A map of the building block of matter. http://www.chemsoc.org/viselements/pages/periodic_table.html

Periodic Table Expanded View The way the periodic table usually seen is a compress view, placing the Lanthanides and actinides at the bottom of the stable.

The Periodic Law Periodic Law- States that chemical and physical properties of the elements repeat in regular, periodic patterns when they are arranged according to their atomic number. Periodic Trends – Repeating patterns that arise by organizing elements according to their atomic number

Lewis Diagrams Lewis Diagrams- are models of the atom showing the chemical symbol and only the valence electrons for that element. Bohr-Rutherford Diagram Lewis Dot Diagram

Valence Electrons- Octet Rule- RULE: ∙ ∙ ∙ ∙ ∙∙ ∙∙ ∙∙ ∙∙ Li Be∙ B∙ ∙C∙ ∙N∙ ∙O: ∙F: :Ne: ∙ ∙ ∙ ∙∙ ∙∙ ∙∙ RULE: Electrons are added one at a time starting at 12 o’clock then 3, 6, 9 o’clock. Electrons do not pair until the 5th electron which is back to 12 o’clock. Valence Electrons- electrons in the valence shell (outer most shell) Octet Rule- when the maximum number of 8 electrons is achieved in their valence shell.

Periodic Table: Metallic arrangement Layout of the Periodic Table: Metals vs. nonmetals Nonmetals Metals

Periodic Table: electron behavior The periodic table can be classified by the behavior of their electrons

Reading the Periodic Table: Classification Nonmetals, Metals, Metalloids, Noble gases

Across the Periodic Table Periods/Rows: Are arranged horizontally across the periodic table (rows 1-7) These elements have the same number of valence shells. 2nd Period 6th Period

Down the Periodic Table Groups/Family: Are arranged vertically down the periodic table (columns or group, 1- 18 or 1-8 A,B) These elements have the same number of electrons in the outer most shells, the valence shell. Alkali Family: 1 e- in the valence shell Halogen Family: 7 e- in the valence shell

Infamous Families of the Periodic Table Notable families of the Periodic Table and some important members: Alkali Alkaline (earth) Transition Metals Noble Gas Halogen

Important members - the Elements Individual members of selected Elements & their characteristics H He Li Na K Ca Mg Fe I Cl F P S Si O N C Al Zn Cu Ag Br

Summary Periodic Table: Map of the Building block of matter Type: Metal, metalloid and Nonmetal Groupings: Representative or main, transition and Lanthanide/Actanides Family: Elements in the same column have similar chemical property because of similar valence electrons Alkali, Alkaline, chalcogens, halogens, noble gases Period: Elements in the same row have valence electrons in the same shell.

Periodic Table e- configuration from the periodic periodic table The Periodic Table can be arrange by subshells. The s-block is Group IA and & IIA, the p-block is Group IIIA - VIIIA. The d-block is the transition metals, and the f-block are the Lanthanides and Actinide metals H 1s1 He 1s2 Li 2s1 Be 2s2 B 2p1 C 2p2 B 2p1 N 2p3 O 2p4 F 2p5 Ne 2p6 Na 3s1 Mg 3s2 Al 3p1 Si 3p2 P 3p3 S 3p4 Cl 3p5 Ar 3p6 K 4s1 Ca 4s2 Sc 3d1 Ti 3d2 V 3d3 Cr 4s13d5 Mn 3d5 Fe 3d6 Co 3d7 Ni 3d8 Cu 4s13d10 Zn 3d10 Ga 4p1 Ge 4p2 As 4p3 Se 4p4 Be 4p5 Kr 4p6 Rb 5s1 Sr 5s2 Y 4d1 Zr 4d2 Nb 4d3 Mo 5s14d5 Tc 4d5 Ru 4d6 Rh 4d7 Ni 4d8 Ag 5s14d10 Cd 4d10 In 5p1 Sn 5p2 Sb 5p3 Te 5p4 I 5p5 Xe 5p6 Cs 6s1 Ba 6s2 La 5d1 Hf 5d2 Ta 5d3 W 6s15d5 Re 5d5 Os 5d6 Ir 5d7 Ni 5d8 Au 6s15d10 Hg 5d10 Tl 6p1 Pb 6p2 Bi 6p3 Po 6p4 At 6p5 Rn 6p6 Fr 7s1 Ra 7s2 Ac 6d1 Rf 6d2 Db 6d3 Sg 7s16d5 Bh 6d5 Hs 6d6 Mt 6d7

The Number of Electrons in Each Energy Level: Max # of electrons 1 1s2 = 2 2 2s22p6 =8 3 3s23p63d10 =18 4 4s24p64d104f14=32

Atomic Orbitals

electrons occupy lowest energy levels available Basic Principle: electrons occupy lowest energy levels available

Aufbau Principle -- “Bottom Up Rule” 22

Pauli exclusion principle An orbital can contain a maximum of 2 electrons, and they must have the opposite “spin.” Hund’s Rule You must fill all subshells of an orbital before doubling up arrows. Example: Determine the electron configuration and orbital notation for the ground state neon atom. 23

2 ways to write electron configurations spdf Notation 1 s value of energy level sublevel no. of electrons spdf NOTATION for H, atomic number = 1 Orbital Box Notation Arrows show electron spin (+½ or -½) ORBITAL BOX NOTATION for He, atomic number = 2 1s 2  24

Shorthand notation practice [Noble Gas Core] + higher energy electrons Examples ● Aluminum: 1s22s22p63s23p1 [Ne]3s23p1 ● Calcium: 1s22s22p63s23p64s2 [Ar]4s2 ● Nickel: 1s22s22p63s23p64s23d8 [Ar]4s23d8 {or [Ar]3d84s2} ● Iodine: [Kr]5s24d105p5 {or [Kr]4d105s25p5} ● Astatine (At): [Xe]6s24f145d106p5 {or [Xe]4f145d106s26p5}

Basic Principle: electrons occupy lowest energy levels available Rules for Filling Orbitals Bottom-up (Aufbau’s principle) Fill orbitals singly before doubling up (Hund’s Rule) Paired electrons have opposite spin (Pauli exclusion principle) 26

Full Configuration: 1s22s22p63s23p3 Valence Configuration: 3s23p3 Phosphorus Symbol: P Atomic Number: 15 Full Configuration: 1s22s22p63s23p3 Valence Configuration: 3s23p3 Shorthand Configuration: [Ne]3s23p3     1s 2s 2p 3s 3p Box Notation 27

Identify examples of the following principles: 1) Aufbau 2) Hund’s rule 3) Pauli exclusion

READ SECTION 1.1, pp.10-12 PRACTICE PROBLEMS Page 14, #1,2,4,6. WORK SESSION  READ SECTION 1.1, pp.10-12 PRACTICE PROBLEMS Page 14, #1,2,4,6.