warm up 10/29

Warm Up 10/29

What is the difference between a mixture and a compound?

Lesson: Intro to Chemical Bonding

Chemical Bond – an attractive force between atoms that is strong enough to enable the group to act as a unit.

What makes atoms bond?

Why do they “want”

to bond?

Dating Game

What do you look for in a soul mate?

Like people, atoms want to feel complete. They

feel complete by fulfilling the Octet Rule.

Sodium Chlorine

Octet rule – atoms tend to react and bond so that they have an outer energy level filled with electrons.• They can do this by gaining or losing electrons.

• Most atoms will have 8 valence electrons after they bond.

• Some will have 2 valence electrons, like hydrogen, helium, lithium, berrylium and boron.

Oxygen shares an electron pair with two hydrogen atoms, so that all of them fulfill the octet rule.

Warm Up 10/30

What electric charge does an atom have if it gains an electron?What if it loses an electron?

Lesson: Ionic Bonding

Sodium chloride

Ionic Bond – electrons are transfered, then the ions attract each other.

General Rules:1) 1 Metal + 1 Non-metal2) Elements on left lose electrons (+), elements on right gain electrons (-).

Ionic Characteristics• Forms crystal structures• High melting and boiling points• Conducts electricity when melted• Can dissolve in water

CaF2

Natural NaCl

Sodium gives an electron to chlorine, so that both of them fulfill the octet rule.

.

.

+1 -1

Magnesium Oxide:

Magnesium Oxygen

+2 -2

..

-1 -1+ 2

BeF2

1. Each person gets 5 cards2. You want to keep ionic matches. Lay aside any you already have in your hand.3. Try to match one of your cards with the one on the table. If you can't, then draw another card and let the next player try. 4. Keep playing until one player runs out, or no one can play anymore. Keep your matches.

Card Game Rules

5. Write the formulas of the ionic compounds you made on paper.• Put the metal 1st and the nonmetal 2nd • If it took more than one atom for either,

write it as the subscript (the little number)

Practice – Left side!Directions: Write the formula units for the following ionic compounds:1) Sodium & oxygen2) Barium & fluorine3) Rubidium & iodine4) Calcium & sulfate (poly)5) Potassium & sulfite (poly)6) Aluminum & oxygen

Polyatomic Ions• Ions made of more than one atom (molecules that are ions)

• All are anions, except ammonium• Have special names

Sulfate

Hydroxide

Phosphate

Warm Up 10/31

Give an example of a homogeneous mixture and a

heterogeneous mixture.

Warm Up 11/1

If you had two liquids that formed a homogeneous mixture, what

method could you use to separate them?

Lesson: Naming Ionic Compounds

How to Name:1. Cation’s name remains unchanged2. Change the end of the anion’s

name to “ide”(polyatomic ion names stay the same)

NaCl = K O = Al (CO ) = 2 3 3

2

Sodium chloride

Aluminum carbonatePotassium oxide

Problem: Some elements have more than one form of cation!

Examples: Fe and Fe

We call them Iron (II) and Iron (III)

Cu and CuCall them Copper (I) and Copper (II)

2+ 3+

+ 2+

Metals with Double Cations:•Ti Ti•Cr Cr•Fe Fe•Cu Cu•Au Au•Sn Sn•Pb Pb

+2

+2

+2

+2

+2

+2

+4

+4

+3

+3

+3

+3

+

+

CuCl = Is it Copper (I) or Copper (II)?

Fe O = Is it Iron (II) or Iron (III)?

2

2 3

Use Reverse Swap & Drop!

What if the reverse ‘Drop and Cross’ method doesn’t work?

Example: FeO

Practice: Left Side!Directions: Write the names of the following ionic compounds.

1.MgO

2.KBr

3.Na O

4.FeCl

5.CuBr

3

2

2

Warm Up 11/12

What is the difference between an ionic compound like salt (NaCl) and a water

molecule (H 0)?2

How many more electrons (dots) does each atom have room for?

Warm Up 11/17

Lesson: Covalent Bonding

How many valence electrons do atoms want?

How many more valence electrons does oxygen need?

Warm Up 11/9

Compound = 2 atoms that are chemically bonded together.

Noble gases don’t chemically react. Why?

They have 8 valence electrons.

Old Ideas

Octet rule – atoms react and bond so that they have an outer energy level filled with 8 valence electrons.(Some atoms only need 2)

New Ideas

Atoms want 8 valence electrons. That means they will have a full outer energy level.

Bonding

Ionic• Electrons transferred

• 1 metal + 1 nonmetal

Covalent• Electrons shared

• 2 nonmetals

What actually holds covalent compounds together? They are both attracted to the shared electron.

2 Chlorine Atoms

Chlorine Molecule1 Shared

pair of Electrons

Methane

Is the following compound ionic or covalent? How do you know?

P O

Warm Up 11/10

2 5

Naming Covalent CompoundsRules: 1)Name of the first element remains the

same (might need a prefix)2)Name of the second element ends in “ide”

(might need a prefix)

Example: S C 3

Prefixes

Practice Naming• PCl

• CO

• N O

• S N

3

2

4 5

2

= Phosphorus trichloride

= Carbon dioxide

= Dinitrogen monoxide

= Tetrasulfur pentanitride

Practice Writing Formulas

• Selenium hexafluoride

• Xenon tetrafluoride

• Dichlorine heptoxide

• Arsenic trifluoride

= SeF6

= XeF4

= Cl O2 7

= AsF3

On Your Own PracticeWrite the Names:1) Br O2) S N3) SCl4) Se F

Write the Formulas:5) Chlorine dioxide6) Selenium tetrafluoride7) Dinitrogen trioxide8) Tetraphosphorus pentasulfide

2

2

445

3

Warm Up 11/13

What is the electron configuration of sulfur?

Cool Down 11/10

Draw the lewis dot structure for NF 3

N.. .

.. F. .

.. ...

. ... .

.F.

. ..

F...

.

Trigonal Pyramidal

Ionic

Metallic

Covalent• 1 Metal + 1

Nonmetal

• Electrons transferred (stolen)

• Swap & Drop

• 2 Nonmetals

• Electrons shared

• Prefixes

Covalent Characteristics• Gases, liquids or solids (molecules)• Low melting and boiling points• Poor conductors of electricity• Usually not soluble in water

Metallic BondingThe valence electrons of metals move

about freely, forming a “sea” of electrons.

Characteristics of Metals

1.Conductive of electricity and heat

2. Ductile3. Malleable 4. Luster

Ionic or Covalent?

Name Formula

P S

Barium fluoride

Fe(OH)

Dinitrogen pentoxide

Potassium phosphate

43

2

Write the names of the covalent compounds:1.P S2.Br O

Write the formulas of the covalent compounds:

3. Carbon heptachloride4. Trinitrogen pentasulfide

62

43

Write the names of the ionic compounds:5.MgBr6.FeN

Write the formulas of the ionic compunds:7.Aluminum oxide8.Copper (II) fluoride

Polyatomic Ions9.Write the name of K PO10. Write the formula of lithium sulfite

2

3 4

Metals with Double Cations:• Ti Ti• Cr Cr• Fe Fe• Cu Cu• Au Au• Sn Sn• Pb Pb

+2

+2

+2

+2

+2

+2

+4

+4

+3

+3

+3

+3

+

+