Ionic and molecular bonding Lesson 9 and 10

reminders - Lab was due YESTERDAY - Creative project due TOMORROW - If you will be away hand it in in the morning or after school - Unit test next TUESDAY - Unit Outline, Test Outline and vocabulary online - Practice problems in textbook - Extra help hmu PERIOD 4

IF YOU LOSE YOUR PERIODIC TABLE

Ion review Ions are atoms with a charge The number of protons does not equal the number of electrons They have lost/gained/shared ELECTRONS (protons never change) They do this because of the octet rule Atoms are most stable with a full valence shell

Complete the table Group Valence Electrons Lose or Gain e- How many? New Charge Cation or Anion 1 Lose +1 Cation 2 13 3 +3 14 15 5 Gain -3 Anion 16 17 7 -1 18 2 Lose 2 +2 Cation 4 Can do both 4 -4 or +4 Can be both 6 Gain 6 -2 Anion 8 Neutral

Where do the lost electrons go?

Bonding Occurs when atoms combine to make a molecule, usually to get a full valence shell Two main types: ionic and molecular bonds

Ionic bonds Bond between METAL and NON-METAL Creates IONIC bond Electrons are TRANSFERRED to get a full valence shell Because atoms are gaining and losing electrons they become IONS

Foldable note Foldable time So much excitement!

Ionic bonds Bond between METAL and NON-METAL Creates IONIC bond Electrons are TRANSFERRED to get a full valence shell Because atoms are gaining and losing electrons they become IONS

Properties of ionic bonds Transfer of electrons (gain/lost) Solid Crystal lattice structure High melting point Soluble in water? Yes Ions dissociate Conduct electricity In solution As liquid

How do ionic bonds happen Lithium chloride Calcium oxide Potassium oxide Aluminum chloride

Steps for bonding Draw the Lewis structures of each element Connect the diagrams with arrows Draw the ions that were made New number of electrons Brackets Charge Write the new charges and cross down Write chemical formula Write name with non-metal ending in ”ide” instead of “ine” or “gen” Make foldable

Examples Sodium and chlorine Magnesium and fluorine Potassium and oxygen Aluminum and sulfur

Foldable note Foldable time So much excitement!

Foldable note Practice time Complete the worksheet

reminders Unit Test next TUESDAY Test and unit outline online Practice problems in textbook Extra help every day PERIOD 4

Molecular bonds Electrons are SHARED between atoms Between NON-METALS Bond is called COVALENT bond

properties OF MOLECULAR COMPOUNDS 2 or more non-metals Electrons are shared State is often liquid or gas Low melting point Soluble in water? Usually no Conduct electricity? Usually no

Diatomic elements F H H O O F N N O O F H F H N N H2 O2 F2 N2 H O F Br I N Cl Atoms that always travel in pairs Example of covalent bonds F H H O O F N N O O F H F H N N H2 O2 F2 N2 same as Br2, I2, Cl2

Steps for bonding Draw the Lewis structures of each element Determine the bonding capacity of each atom Circle shared electrons. Check for full octet. Redraw structural diagram with lines. Write molecular formula based on structural diagram. You will not have to name the compound in Grade 9 (but your foldable will tell you how) Make foldable

More examples hydrogen and chlorine oxygen and hydrogen nitrogen and iodine

Building molecular compounds with models

Metallic bonding Between METALS Electrons delocalize Have positive ions in a sea of electrons

Electrical Conductivity BONDING OVERVIEW Compound Ionic Molecular Metallic Atoms Metal and non metal Non metals Metals Type of Bond Covalent Electron are Transferred, Gain/Lost Shared Delocalized Structure Crystal lattice True molecules Electron sea Physical State Solid Liquid or gas Melting Point High Low Very high Soluble in Water Yes Usually no No Electrical Conductivity In solution or liquid Ions are formed