5. Ionic bonding Flashcards
What is an ion?
An atom which has lost or gained electron(s)
What kind of elements take part in ionic bonding?
Metals reacting with non-metals
Why do metals lose electrons to form positive ions?
To obtain a full outer shell
How many electrons do metals lose to form ions?
The number of valence electrons that they have.
e.g Na loses 1
Mg loses 2
What charge do metal ions have when they lose electrons?
They take on the corresponding positive charge as the number of electrons they lose.
e.g Mg loses 2 electrons to become Mg2+
Why do non-metals form negative ions?
They gain electrons (-1 charge) to complete their outer shell.
Why is water a “polar” molecule?
Why are many ionic compounds soluble in water?
Do ionic substances conduct in
- Solid state
- Solution
- Liquid state
- No
- Yes
- Yes
Why do ionic substances conduct in solution but not in solid state?
The ions are free to move in solution but are trapped in the lattice in the solid.
Do ionic compounds have low or high melting points?
High
Why do ionic compunds have high melting points?
What is meant by a lattice?
A regular, repeating, 3-D structure.
Recognising the diagram of an ionic lattice
What is electrolysis?
The breaking apart of an ionic substance using electricity
What haapens at the negative electrode during electrolysis?
Reduction of metal ions into metal atoms.
What happens at the positive electrode during electrolysis?
Oxidation
Negative ions lose electrons to form atoms (usually as molecules)
