Transcript Stable Octets

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
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Full outershells = NO REACTION!
Stable Octets
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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
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To do this the elements must either
GIVE electrons or TAKE electrons.
Charged Ions
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If an element GIVES away electrons, it will
become positively charged. Why?
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If an element TAKES electrons, it will
become negatively charged. Why?
The Pool Analogy
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Your job is to clean pools. You must either
completely fill or completely empty each pool. You
have the choice.
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The pool will already have a level
of water in it. Level 0 to 8.
8
7
6
5
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The pool is divided into 8 sections.
To get the most pools empty or full,
what are you going to do?
4
3
2
1
0
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Level 5 up:
Fill the pool=
GAIN
8
7
6
5
4
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Level 4
down: Empty
the pool =
GIVE
3
2
1
0
8
7
6
5
4
Who Gives and Who Takes?
3
2
1
0
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Elements with 4 or less valence electrons will GIVE
their electrons away.
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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?
Cations and Anions
An ion is an atom that has a charge.
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To GIVE away electrons= positive charge
–
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CATION
To TAKE electrons= negative charge
–
ANION
LABORATORY SAFETY
Safety in the Lab is very
important. Strict rules must
be followed at all times.
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WHMIS: Workplace Hazardous Materials
Information System
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WHMIS
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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
Oxygen
Propane
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
Propane
Acetone
Kerosene
Magnesium
Sodium
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
D2 Materials causing other
toxic effects
Products whose health effects generally appear over time following
one or several exposures
Benzene
Diisocyanates
Lead
D3 Biohazardous infectious
materials
Living organisms or their toxins that can cause disease in people or
animals
AIDS virus
Hepatitis B virus
Rabies virus
E
Corrosive materials
Products that can corrode metal surfaces or cause burns to skin
Caustic soda
Hydrochloric acid
Bleach
F
Dangerously reactive
materials
Products that can be health or safety hazards under certain conditons
(pressure, temperature, impact, violent reaction with water or air)
Fluorine
Hydrogen cyanide
B-Chloroprene
Phenol
Safety Assignment
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Due This Friday- Feb 27!!
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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.
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Can be a written story, comic strip, cartoon etc.
BE IMAGINATIVE!
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