IONS h?v=WWc3k2723IM UNIT 1B.10 h?v=WWc3k2723IM h?v=WWc3k2723IM Ionic Bonding =hiyTfhjeF_U =hiyTfhjeF_U

The Bohr Model of the Atom A.Electrons of hydrogen circle the nucleus in orbits 1. orbits have a fixed amount of ______ 1. orbits have a fixed amount of ______ in the ground state in the ground state 2. orbits are a fixed ________ from the 2. orbits are a fixed ________ from the nucleus nucleus 3. orbits furthest from the nucleus have 3. orbits furthest from the nucleus have the ________ energy the ________ energy

Niels Bohr (1885 – 1962) Bohr Model of the Atom

Bohr’s Model Nucleus Electron Orbit Energy Levels

Bohr’s Model Increasing energy Nucleus First Second Third Fourth Fifth }  Further away from the nucleus means more ________.  There is no “in between” energy  Energy Levels

IONS  An atom usually has a ______charge. That means it has the same number of _____ as ________  Remember, a proton has a positive charge and an electron has a negative charge  ION – an atom that has lost or _____ one or more electrons and has become charged either ______ or ________

Positive Ions  When an atom LOSES electrons, it becomes more _________ –Why?  If you are getting rid of ______ particles (electrons) but your number of positive particles (______) are staying the same. –In other words, you are subtracting negative numbers

Examples  What would the charge be if:  The neutral form of Gold (Au) lost 4 of its 79 electrons. It now has 79 protons and _____electrons  The neutral form of Mg lost 2 of its 12 electrons. It now has __ protons and 10 electrons.

Negative Ions  When an atom GAINS electrons it becomes more _________ –Why?  Electrons have a _______ charge, so the more you have, the more negative you become

Representing Ions  Ions are represented by placing a “superscript” charge number next to the atomic symbol.  Ex. –O -2 = oxygen with a negative __charge –K + = potassium with a ______ 1 charge –N -3 = nitrogen with a _______ 3 charge –And so on

Keeping Track of Electrons 2. Atoms in the same column a. Have the same outer _______ configuration. b. Have the same ________ electrons. c. Easily found by looking up the group number on the ________ table. d. Group 2A - Be, Mg, Ca, etc.- 2 ________ electrons

 List the number of valence shell electrons are in each of the elements in groups 

B. Electron Dot Diagrams: Lewis Structures 1. A way of keeping track of _______ electrons. 2. How to write them 3. Write the symbol. 4. Put one ___ for each valence electron 5. Don’t pair up until they have to X

The Electron Dot diagram for Nitrogen l Nitrogen has __ valence electrons. l First we write the symbol. N l Then add __electron at a time to each side. l Until they are forced to pair up.

Write the electron dot diagram for Na Na Mg MgCOFNeHe

C. Ion Formation in Representative Elements Group Gain or Lose Charge of Ion 1 (1A) lose (2A) lose (3A) lose (4A) lose or gain 4* +4,-4* 15 (5A) gain (6A) gain (7A) gain 1 -1

Electron Dots For Cations  Metals will have few valence electrons Ca

Electron Dots For Cations  Metals will have few valence electrons  These will come ____ Ca

Electron Dots For Cations  Metals will have few valence electrons  These will come off  Forming _______ions Ca +2

D. Electron Configurations for Anions 1. Nonmetals gain _______ to attain noble gas configuration. 2. They make ______ ions.

Electron Dots For Anions  Nonmetals will have many ______.electrons.  They will gain electrons to fill _____ shell. P P -3

E. Stable Electron Configuration 1.All atoms react to achieve noble gas configuration valence electrons. 3. Also called the octet rule. Ar

Write the electron configuration diagram label as anion or cation  Na  Mg PPPP OOOO FFFF  Cl KKKK

 quiz

I. Properties of Ionic Compounds View Ionic video a. Crystalline structure. b. A regular ________ arrangement of ions in the solid. c. Structure is rigid.

I. Chemical Bonds  A. The force that holds two atoms together. 1. Why do atoms form bonds? 1. Why do atoms form bonds? a. to acquire ___electrons in the a. to acquire ___electrons in the valence shell (like noble gases 2. How do atoms form bonds? valence shell (like noble gases 2. How do atoms form bonds? a. atoms may lose, ____ or share a. atoms may lose, ____ or share electrons to get 8 in the ______ electrons to get 8 in the ______ shell shell

A. Chemical Bond and valence electron 1.The electrons responsible for the chemical properties of atoms are those in the outer energy level: ____________________. a.Valence electrons - The electrons in the outer _______ level. b.Inner electrons -those in the energy _______ below.

II. Ionic Bonding A. Anions and cations are held together by _________ charges. B. Ionic _________ are called salts. C. Simplest ratio is called the formula unit. D.The bond is formed through the transfer of __________. E. Electrons are transferred to achieve _____ gas configuration.

II.Formation and Nature of Ionic Bonds F. 1. atom “M” loses electron(s)  ______ 2. atom “N” gains electron(s)  anion 2. atom “N” gains electron(s)  anion 3. cation and ______ attract each other 3. cation and ______ attract each other a. electrostatic attraction a. electrostatic attraction 4. the electrostatic force that holds the 4. the electrostatic force that holds the oppositely charged ____ together is oppositely charged ____ together is the ______ bond the ______ bond

Sodium loses an electron forming a (+) ion. Chlorine gains an electron forming a ( - ) ion. ________ attraction between the (-) and (+) ion forms the ______bond between sodium and chlorine ________ attraction between the (-) and (+) ion forms the ______bond between sodium and chlorine

B. Ionic Compounds 1. compounds containing ______ bonds 1. compounds containing ______ bonds 2. types of ionic compounds 2. types of ionic compounds a. oxides – metal + ________ a. oxides – metal + ________ Na 2 O, CaO, Al 2 O 3, Fe 2 O 3 Na 2 O, CaO, Al 2 O 3, Fe 2 O 3 b. salt – metal + _________ b. salt – metal + _________ NaCl CaF AgCl KI NaCl CaF AgCl KI c. binary compounds – two elements c. binary compounds – two elements 1)all of the compounds in a and b 1)all of the compounds in a and b are binary compounds are binary compounds

 D. monoatomic ion - ____atom 1) ex. K + Fe 3+ O 2- N 3- 1) ex. K + Fe 3+ O 2- N 3- E. polyatomic ion – ion with more than E. polyatomic ion – ion with more than one atom that acts as a _____ ion one atom that acts as a _____ ion NO 3 - OH - SO 4 2- NH 4 + NO 3 - OH - SO 4 2- NH 4 +

III. Names and Formulas A.Formulas for Ionic Compounds 1. vocabulary 1. vocabulary a. formula unit – simplest _____ of a. formula unit – simplest _____ of ions in a compound ions in a compound 1) ex. NaCl MgBr 2 AlCl 3 1) ex. NaCl MgBr 2 AlCl 3 b. monoatomic ion - ___ atom b. monoatomic ion - ___ atom 1) ex. K + Fe 3+ O 2- N 3- 1) ex. K + Fe 3+ O 2- N 3-

B. Formulas For Ionic Compounds 1. write formula for the ______ first, then 1. write formula for the ______ first, then the ______ the ______ 2. use ________ to indicate number of 2. use ________ to indicate number of ions (criss-cross the charges) ions (criss-cross the charges) a. sum of charges should equal 0 a. sum of charges should equal 0 b. never change subscripts in b. never change subscripts in __________ __________

Sodium Chloride Crystal

Ionic Bonding NaCl

Ionic Bonding: Lewis Structure Na + Cl -

Ionic Bonding  All the electrons must be accounted for! CaP

Ionic Bonding CaP

Ionic Bonding Ca +2 P

Ionic Bonding Ca +2 P Ca

Ionic Bonding Ca +2 P -3 Ca

Ionic Bonding Ca +2 P -3 Ca P

Ionic Bonding Ca +2 P -3 Ca +2 P

Ionic Bonding Ca +2 P -3 Ca +2 P Ca

Ionic Bonding Ca +2 P -3 Ca +2 P Ca

Ionic Bonding Ca +2 P -3 Ca +2 P -3 Ca +2

Ionic Bonding Ca 3 P 2 Formula Unit

Shortcut  Ca +2 P -3  Ca 3 P 2  Crisscross the charges to become the subscript!!!!!!!!!!!!!!!!!!!!!!!!!

I. Properties of Ionic Compounds a. Crystalline structure. b. A regular repeating arrangement of ions in the solid. c. Structure is rigid.

Crystalline structure

Ionic Compounds Ionic compounds consist of a ______ a ______ of positive of positive and _______ ions. Lattice: three dimensional array of ______ NaCl:

Ionic properties d. Ions are strongly bonded- because of strong forces between ions they have 1.______melting points 2. high _______ point 2. high _______ point 3. high hardness _______ 4. very ______ 5. _______ brittle

Ionic solids are brittle

 Strong Repulsion breaks crystal apart.

E. Conductivity E. Conductivity 1.Conducting electricity is allowing charges to move. 2.In a solid, the ions are locked in place. 3. Ionic solids are insulators. 4. When melted, the ions can move around. 5. Melted ionic compounds conduct. 6. First get them to 800ºC. 7. ELECTROLYTE-Dissolved in water they conduct. (aqueous solution)

Building Ionic Compounds Binary compound - metallic cation bonded to nonmetallic anion 1. Oxide- When a metal is ionically bonded to Oxygen Salt - Metal + Non-metal

Polyatomic Ions  An ion made up of two or more atoms bonded together that acts as a single unit with a net charge. Build with tabs NH 4, OH, Write the polyatomic ion and the charge it has. Na(OH)- a balance compound Mg +2 (OH ) –1 Mg(0H) 2 a balanced compound Mg(0H) 2 a balanced compound

ACTIVITY:   MAKE TAB CUTOUTS OF THE VALENCE SHELL OF   AL, O, Na, Cl, Mg, Ca   Bond Al O   Mg O   Na Cl  Build just one formula unit- remember it doesn’t exist as one i  Build just one formula unit- remember it doesn’t exist as one in nature – it is a crystal of many formula units where each – is surrounded by a +

Activity  Demo- Burn to Create Mg+O=MgO  Check the conductivity of:  1. NaCl- solid  2. NaCl-aqueous solution  3. Distilled water  4. Tap  5. MgO-solid  6. MgO-aqueous solution  7. use magnifying glass to view NaCl

I. Metallic Bonds  How atoms are held together in the solid form.  Metals hold onto their _______ electrons very weakly.  Think of them as _______ ions floating in a sea of electrons.

 LHY LHY LHY

Sea of Electrons  Electrons are ______to move through the solid.  Metals ________electricity.

Metals are Malleable  __________ into shape (bend).  ________ - drawn into wires.

Malleable

Malleable  _________allow atoms to _______ by.

Video  47s 47s 47s

ALLOYS  Alloys are ___________made by dissolving metals in other metals. They are prepared by melting the metals together and cooling the mixture.  The properties of alloys differ from those of their component metals. For example ____________, an alloy of iron, carbon, chromium and nickel is stronger than iron and more resistant to corrosion.

Name of Alloy Composition ________________________________________ Sterling silver silver, copper Brass copper, zinc, tin Cast iron iron, carbon Steel iron, carbon Stainless steel iron, chromium, carbon, nickle 18 Carat gold gold, silver, copper Pewter tin, copper, bismuth, antimony Plumber’s solder lead, tin

ALLOY  A combination of 2 metals

IV.Metallic Bonds – Properties of Metals A.Metallic Bonds 1. valence electrons are _________ 1. valence electrons are _________ a. free to move from atom to atom a. free to move from atom to atom 2. bond is formed by the attraction of 2. bond is formed by the attraction of metal cations for the moving electrons metal cations for the moving electrons 3. ______________” –atoms of 3. ______________” –atoms of metals contribute a “sea” of free metals contribute a “sea” of free moving electrons that move from one moving electrons that move from one atom to another atom to another

Electron Sea Model for Metallic Bonds

Positive Ions Surrounded by Delocalized Electrons

B.Properties of Metals 1. moderately high melting points 1. moderately high melting points 2. high boiling points 2. high boiling points 3. ___________ 3. ___________ a. can be hammered into sheets a. can be hammered into sheets 4. ___________ 4. ___________ a. can be drawn into wire a. can be drawn into wire 5. good conductors of heat and electricity 5. good conductors of heat and electricity 6. _________ (good reflectors of light) 6. _________ (good reflectors of light) 7. hardness and strength varies 7. hardness and strength varies a. greater in transition elements a. greater in transition elements

C. Alloys 1. mixture of two or more elements with 1. mixture of two or more elements with metallic properties metallic properties 2. types 2. types a. substitutional – atoms of similar a. substitutional – atoms of similar size (sterling silver, brass, pewter) size (sterling silver, brass, pewter) b. interstitial – small holes in the b. interstitial – small holes in the crystal filled with smaller atoms crystal filled with smaller atoms (carbon steel) (carbon steel)