Ionic bonding Flashcards
Ionic compounds
oppositely charged ions held together by electrostatic attractions
Molecular ions
Hydroxide = OH-
Nitrate = NO3-
Ammonium = NH4+
Sulfate = SO42-
Carbonate = CO32-
How can you work out the formula of an ionic compound ?
By using the swap and drop method
What affects the strength of an ionic bond ?
- ionic charge
- ionic radius
Ionic charge
Higher charge = stronger electrostatic attraction
Ionic radius
Smaller charge = stronger electrostatic attraction
Properties of ionic compounds
- dissolve in water as water molecules are polar they can attract the positive and negative ions and break up the structure
- conducts electricity when molten or dissolved in solution as the ions are free to move around
- high melting points as there are many electrostatic forces between oppostively charged ions lots of enery needed to overcome these forces
- brittle - layers slide so postive ions aligned with positives and negative ions align with negative, they repel and structure breaks apart
Ionic radius … as we go down a group
increases
As we go down the group the number of electron shells … and so the ionic radius increases too
increases
Isoelectric ions
these are different atoms that have the same number of electrons
Ionic radius in isoelectric ions … as the atomic number increases
decreases