Chapter 3 – Chemical Compounds
A compound
Naming compounds
- ide means
- ate means
Section A - The Noble gases
 All have ____________________________ so do not bond with other
elements. They are very _____________________.
 Uses:
Helium:
Argon:
Section B: Valancy and the Octet rule
Octet rule
Exceptions to the octet rule:
1.
2.
Valancy
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Chapter 3 – Chemical Compounds
 Using the octet rule to predict simple chemical formulas
The Criss Cross method:
The valancy of complex ions
The valancy is the same as the charge on the ion ( but cannot be negative)
Valancy
Hydroxide OH-
1
Nitrate
Sulfite SO3-2
carbonate
Hydrogen carbonate
Sulfate
 Transition metal ions
Can have __________ valancy – valancy changes depending on what
they are bonded to
Examples:
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Chapter 3 – Chemical Compounds
Self assessment of your learning of
Chemical Compounds
Green = I have learnt this
Orange = I am not sure – have to revise this
Red = I don’t know this yet – have to learn
Can you….
Define Compound
Interpret simple chemical formulas
Understand why noble gases are so stable
Explain some uses of helium and argon that are related to
their chemical unreactivity.
Define valancy
State the Octet rule
Give some limitations of the octet rule (when doesn’t it
work?)
Higher level only
Name some transition elements that have variable
valancies
Use the octet rule to predict the formulas of simple
compounds
Know the formula and the valancy of the hydroxide ion
Know the formula and the valancy of the carbonate ion
Higher level only
Know the formula and the valancy of the nitrate ion
Higher level only
Know the formulas and the valancy of the
hydrogencarbonate ion
Higher level only
Know the formulas and the valancy of the sulfite ion
Higher level only
Know the formulas and the valancy of the sulfate ion
Higher level only
Use the octet rule to predict the formulas of compounds
including hydroxides, carbonates, nitrates, hydrogen
carbonates, sulfites and sulfates
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Green
Orange
Red
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