Unit2Day4-VandenBout Monday, September 30, 2013 1:30 PM Vanden Bout/LaBrake/Crawford CH301 ELECTRON CONFIGURATION and BONDING Where did all that salt come from? UNIT 2 Day 4 CH301 Vanden Bout/LaBrake Fall 2013 Important Information LM18 Posted DUE TH 9AM Study Ionic and Covalent Bonding and Nomenclature on Fundamentals Nomenclature Quiz Th Laude LM Lecture 7 CH301 Vanden Bout/LaBrake Spring 2013 Unit2Day4-VandenBout Page 1
What are we going to learn today? − Electron Configuration and Bonding • Relate the valence shell electron configuration to bonding • Understand the similarities and differences between ionic and covalent bonding • Recognize and name compounds based on elemental composition CH301 Vanden Bout/LaBrake Fall 2013 QUIZ: CLICKER QUESTION 1 The trend on the periodic table is that atomic radii: a) Increases as you move from L to R across b) Decreases as you move from R to L across c) Increases as you move from T to B down d) Increases as you move from B to T up e) Both b and c CH301 Vanden Bout/LaBrake Fall 2013 QUIZ: CLICKER QUESTION 2 Which of the following symbols does not match the elemental name? A.Fe - Iron B.As – Arsenic C.Co – Copper D.Sn – Tin Unit2Day4-VandenBout Page 2 E.V - Vanadium
match the elemental name? A.Fe - Iron B.As – Arsenic C.Co – Copper D.Sn – Tin E.V - Vanadium CH301 Vanden Bout/LaBrake Fall 2013 QUIZ: CLICKER QUESTION 3 At the end of the last class period we saw a demo. Two metals were tossed into water and something happened. a)The metals sank to the bottom of the bucket b)The metals floated in the bucket c)The metals spun around the surface of the water and then burst into flames d)This is not true, just a trick question for the 75 people who were absent Thursday CH301 Vanden Bout/LaBrake Fall 2013 Unit2Day4-VandenBout Page 3
Where are the electrons in Ne? 1s 2 2s 2 2p 6 very stable gas Z=10 Where are the electrons in Na? [Ne]3s 1 not so stable metal Z=11 Where are the electrons in K? [Ar]4s 1 more, not so stable metal Z=19 CH301 Vanden Bout/LaBrake Fall 2013 Shielding and Effective Nuclear Charge Left to Right Z eff is increasing Top to Bottom Z eff is similar Top to Bottom. Electron in higher in Energy. Farther from the nucleus THIS CAN EXPLAIN A LOT ABOUT THE PERIODIC TABLE CH301 Vanden Bout/LaBrake Fall 2013 Trend: Atomic Radii Unit2Day4-VandenBout Page 4
Atomic Radii CH301 Vanden Bout/LaBrake Fall 2013 CH302 Vanden Bout/LaBrake Fall 2012 EXPLAIN SPIKE IN IONIZATION ENERGY! CH302 Vanden Bout/LaBrake Fall 2013 Unit2Day4-VandenBout Page 5
Based on this trend in ionization energies this element is A. argon B. carbon C. magnesium D. sulfur CH301 Vanden Bout/LaBrake Fall 2013 SHOW SOME ELECTRON CONFIGURATIONS OF IONS CH301 Vanden Bout/LaBrake Fall 2013 Unit2Day4-VandenBout Page 6
CH302 Vanden Bout/LaBrake Fall 2012 POLL: CLICKER QUESTION 4 Where did this guy get all of that salt (NaCl)? a)It formed from Na + and Cl - ions in the water b)He first pitch a few block of Na metal into a pool and then bubbled in Cl 2 gas. c)He add the Cl 2 gas to the water that already had Na + ions. d)He added Na metal to the water that already had Cl - ions. CH301 Vanden Bout/LaBrake Fall 2013 ELECTRON LEAVES.. WHERE DOES IT GO? Metals tend to give up electrons to nonmetals, in each case the valence is “ satisfied ” Sometimes is complicated… eg in the sodium in water demo Sometimes is more obvious… 2Na(s) + Cl 2 (g) 2NaCl(s) Unit2Day4-VandenBout Page 7
each case the valence is “ satisfied ” Sometimes is complicated… eg in the sodium in water demo Sometimes is more obvious… 2Na(s) + Cl 2 (g) 2NaCl(s) Sometimes they are already gone! CH301 Vanden Bout/LaBrake Fall 2013 Formation of Ionic Compound – Downhill in Energy CH301 Vanden Bout/LaBrake Fall 2013 Ionic Compound… downhill in energy….. CH301 Vanden Bout/LaBrake Fall 2013 Unit2Day4-VandenBout Page 8
Ionic Compounds… Not a discrete pair of ions…it is a whole collection CH301 Vanden Bout/LaBrake Fall 2013 POLL: CLICKER QUESTION 5 Coulomb ’ s Law Lattice energy depends on Coulomb ’ s Law and the crystal structure (the way the ions are packed together). Assuming the same crystal structure, which do you think would have the larger lattice energy: a)NaF b)NaBr? CH301 Vanden Bout/LaBrake Fall 2013 Ionic Radius Unit2Day4-VandenBout Page 9
CH301 Vanden Bout/LaBrake Fall 2013 Polyatomic Ions Calcium Carbonate Ca 2+ 2- CO 3 Know the names and formulas for all the common polyatomic ions. See the Data & Tables under “ more ” on the eBook CH301 Vanden Bout/LaBrake Fall 2013 Unit2Day4-VandenBout Page 10
POLL: CLICKER QUESTION 6 Naming Ionic Compounds Choose the formula that corresponds to: sodium oxide a)NaO b)NaO 2 c)Na 2 O d)Na 2 O 2 CH301 Vanden Bout/LaBrake Fall 2013 Naming Ionic Compounds You need to be able to name common ionic compounds and with elemental ions and polyatomic ions. WEBSITE – FUNDAMENTALS – DO THE WORKSHEETS CH301 Vanden Bout/LaBrake Fall 2013 What about compounds that aren ’ t ionic.. Covalent? How are they formed? Are electrons lost???? No.. They are “ shared ” …… (two non- metals… two elements with similar electronegativities) Unit2Day4-VandenBout Page 11
’ No.. They are “ shared ” …… (two non- metals… two elements with similar electronegativities) CH301 Vanden Bout/LaBrake Fall 2013 Covalent Compounds Characterize the bond…. Bond Length Bond Strength Electron Pair Shared Equally? YES – PURE COVALENT NO – POLAR COVALENT SHOW THE SIMULATOR….. CH301 Vanden Bout/LaBrake Fall 2013 CH301 Vanden Bout/LaBrake Fall 2013 Unit2Day4-VandenBout Page 12
Electronegativity-electron pulling power of an atom when it is part of a molecule • When one atom is more electronegative than another in a bond, a polar covalent bond is formed. Degree of polarity is dependent on difference in electronegativities . CH301 Vanden Bout/LaBrake Fall 2013 Unit2Day4-VandenBout Page 13
Ionic vs Covalent Bonds • All bonds can be viewed as hybrids between purely ionic and purely covalent • When two identical atoms are bound, it is purely covalent. • When two different atoms are bound, one may have a greater attraction for electrons, and have a partial negative charge. • Polar covalent bond – degree is measured as dipole moment • When one atom has a much stronger attraction to the electrons than the other, an electron may be donated yielding an ionic bond. Covalent Compounds - Naming CH301 Vanden Bout/LaBrake Fall 2013 Unit2Day4-VandenBout Page 14
Covalent Compounds What is attached to what? Valence electrons – Lewis symbols – Lewis Structure – Satisfy the Octet H 2 CH 4 CH301 Vanden Bout/LaBrake Fall 2013 What have we learned? NUCLEAR CHARGE FELT BY VALENCE ELECTRONS IS SHIELDED BY THE CORE ELECTRONS ATOMS BEHAVE IN CERTAIN PREDICTABLE WAYS WHICH CAN BE CORRELATED TO THE ELECTRON CONFIGURATIONS IONIC BONDS TEND TO FORM BETWEEN METALS AND NONMETALS COVALENT BONDS TEND TO FORM BETWEEN NONMETALS AND NONMETALS NAMING COMPOUNDS IS IMPORTANT AND NECESSARY CH301 Vanden Bout/LaBrake Fall 2013 Unit2Day4-VandenBout Page 15
Learning Outcomes Identify metals and non-metals and predict types of compounds (ionic/covalent) Between different elements Relate coulombs law and lattice energy Name basic binary ionic compounds including polyatomic ions Name basic covalent compounds containing two elements Explain the trends in electro-negativity on the periodic table Differentiate between pure covalent and polar covalent bonds CH301 Vanden Bout/LaBrake Fall 2013 Unit2Day4-VandenBout Page 16
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