Homework – Due Fri 12/17/10

Reread Sec 5.3 in your textbook.

Copy the Section Summary on p 162.

Answer Ques # 26-30, 33 on p 162

RemindersTurn in last week’s homework today if you

did not already do soCompleting this week’s homework will

entitle you to a raffle ticket for Friday (in class raffle of a few miscellaneous items)

There will probably be a quiz later this week - TBA

Topics this week are: Valence electrons, electron dot diagrams, ions, ionic bonding

HAPPY MONDAY : )12-13-10

1.Cornell Notes2.Practice Worksheet

3.Partner Practice

Electrons are responsible for HOW ELEMENTS REACT

That is why we learned how to: Write electron configurations Draw electron orbital diagrams

When we understand electrons we can predict how elements will behave (what we

can do with them) Understand the structure of the periodic table

The specific electrons responsible for the chemical properties of an element

Electrons in an atoms outermost orbitals

They are in the highest energy levels

1. Write the electron configuration

O8 1s2 2s2 2p4

2. Circle the subshells in the highest energy levels

O8 1s2 2s2 2p4

3. Count the electrons in those orbitals

O8 1s2 2s2 2p4

2 4+ = 6

How many valence electrons does Magnesium have?

1. Write the electron configuration2. Circle the subshells in the highest energy level3. Count the electrons in those orbitals

Mg12 1s2 2s2 2p6 3s2

2!

How many valence electrons does Chlorine have?

1. Write the electron configuration2. Circle the subshells in the highest energy level3. Count the electrons in those orbitals

Cl17 1s2 2s2 2p6 3s2

2

3p5

5+ = 7!

Used to represent the valence electrons in an element

1. Draw the element SYMBOL

2. Dots representing electrons are placed around the four sides of the symbol one at a time

Oxygen

6 valence electrons O

What is the electron dot structure of Magnesium?

What’s the symbol of magnesium?

How many valence electrons? 2

Mg

What is the electron dot structure of Chlorine?

What’s the symbol of chlorine?

How many valence electrons? 7

Cl

What is the electron configuration of Fluorine?

What is the electron dot structure of Fluorine?

What do fluorine and chlorine have in common?

What family are fluorine and chlorine in?

1s2 2s2 2p5

F ClSame number of valence electrons!

Halogens

Valence electrons are responsible for how elements react

Elements in the same group have the SAME NUMBER OF VALENCE ELECTRONS – that’s why they have similar properties

You’ll be working on your ownSelect one activity card at a timeWrite down which activity card you selectComplete the problems on the back of

your worksheetWhen you are finished, have the teacher

check itOnce it’s correct, you can grab a new cardFull credit = two cards doneBonus points for three or more cards