Stable Octets

Why are the Noble Gases unreactive?

The Noble Gases

Elements in Group 8 This means they have 8 valence electrons

(He has 2) There outermost electron shells are full. (He is still full) This is called a stable octet

Full outershells = NO REACTION!

Stable Octets

All other elements want to achieve stable octets.

They want to BE like a Noble Gas.

The Noble Gases are happy all by themselves, and the other elements want to be like this

To do this the elements must either GIVE electrons or TAKE electrons.

Charged Ions

If an element GIVES away electrons, it will become positively charged. Why?

If an element TAKES electrons, it will become negatively charged. Why?

The Pool Analogy

Your job is to clean pools. You must either completely fill or completely empty each pool. You have the choice.

The pool will already have a level of water in it. Level 0 to 8.

The pool is divided into 8 sections. To get the most pools empty or full, what are you going to do?

8

7

6

5

4

3

2

1

0

Level 5 up: Fill the pool= GAIN

Level 4 down: Empty the pool = GIVE

8

7

6

5

4

3

2

1

0

Who Gives and Who Takes?

Elements with 4 or less valence electrons will GIVE their electrons away.

Elements with 5 or more valence electrons will TAKE electrons.

Question: If I am Calcium and I give away 2 electrons, will I have more electrons or more protons? What does this mean?

8

7

6

5

4

3

2

1

0

Cations and Anions

An ion is an atom that has a charge.

To GIVE away electrons= positive charge – CATION

To TAKE electrons= negative charge– ANION

LABORATORY SAFETY

Safety in the Lab is very important. Strict rules must be followed at all times.

WHMIS: Workplace Hazardous Materials

Information System

WHMIS

A: Compressed Gas B: Combustible Material C: Oxidizing Material

D1: Seriously Toxic D2: Other Toxic D3: Biohazardous

E: Corrosive Material F: Reactive Material

     Classes Definition Examples

                     A    Compressed gases Products held under pressure OxygenPropane

                     B    Flammable and       combustible materials      B1 Flammable gases      B2 Flammable liquids      B3 Combustible liquids      B4 Flammable solids      B5 Flammable aerosols      B6 Reactive flammable materials

Products that will burn or catch on fire easily PropaneAcetoneKeroseneMagnesiumSodium

                     C    Oxidizing materials Products that can cause or promote combustion of another material (whether or not they are themselves combustible) or products that are organic peroxides

Hydrogen peroxide

Nitric acid

                     D1  Materials causing       immediate and serious       toxic effects

Products that can rapidly cause harmful health effects, including death Carbon monoxide

Phenol

                     D2  Materials causing other       toxic effects

Products whose health effects generally appear over time following one or several exposures

BenzeneDiisocyanatesLead

                     D3  Biohazardous infectious       materials

Living organisms or their toxins that can cause disease in people or animals

AIDS virusHepatitis B virusRabies virus

                     E    Corrosive materials Products that can corrode metal surfaces or cause burns to skin Caustic sodaHydrochloric acidBleach

                     F    Dangerously reactive       materials

Products that can be health or safety hazards under certain conditons (pressure, temperature, impact, violent reaction with water or air)

FluorineHydrogen cyanideB-Chloroprene

Safety Assignment

Due This Friday- Feb 27!!

You will create a scenario in which there is a question of safety in the lab. You will ask the reader a question about the story created, and you will answer it using the proper safety rules discussed.

Can be a written story, comic strip, cartoon etc. BE IMAGINATIVE!