1.4 a/b/d: Ionic vs Covalent Bonds

​Syllabus dot points

1.4 b investigate the differences between ionic and covalent compounds through:

– using nomenclature, valency and chemical formulae (including Lewis dot diagrams) (ACSCH029)

– examining the spectrum of bonds between atoms with varying degrees of polarity with respect to their constituent elements’ positions on the periodic table

– modelling the shapes of molecular substances (ACSCH056, ACSCH057)

​What we will cover

• numerically determining difference between ionic and covalent bonds

• how we demonstrate them

• ​properties of ionic and covalent substances

• ​types of solids formed

​How do we determine what kind of bond forms?

• ​metallic quality (we already know this)

• what is is actually based on is electronegativity

• to form a compound, one atom must have a higher electronegativity than the other ​

• the higher the electronegativity difference, the more likely there will be a complete transfer = ionic bond

• ​>1.5 = ionic (ish!)

• <1.5 = covalent

How we demonstrate bonds

• word representations

• formula​/symbol

• diagrams - Lewis/electron dot ​

​Single, double, and triple covalent bonds

The number of bonds an atom needs to make is dependent on the amount of electrons it needs to gain.

Some molecules are not able to satisfy the octet rule by only making single bonds between atoms., they need to share multiple atoms.

​Properties of ionic and covalent molecular substances

​Ionic Properties

​Covalent molecular substances

​Common solid types

Next up

• polarity

• ​predicting shapes of molecules

• ​intermolecular and intramolecular forces