2. Bonding, Structure and the Properties of matter (Ions, Ionic and Metallic Bonding) Flashcards
What are ions?
Ions are charged particles due to the loss or gain of electrons
What are positive ions called?
Cations
What are negative ions called?
Anions
How are positive ions formed?
When an atom loses electrons, which are negatively charged, the overall charge becomes positive
How are negative ions formed?
When an atom gains electrons, which are negatively charged, so the overall charge becomes negative
What ions do Group 1 atoms form?
+1 ions
What ions do Group 7 atoms form?
1-
What ions do Group 2 atoms form?
2+
What ions do Group 6 atoms form?
2-
What are group 7 ions called?
Halide ions
What is an ionic bond?
The strong electrostatic force of attraction between a positively charged ion and a negatively charged ion between a metal and non-metal
What is ionic bonding between?
A metal and a non-metal
What does ionic bonding involve?
The transferring of electrons
Explain how an Ionic bond works?
- In order to gain a full outer shell, the metal will transfer electrons to the non-metal
- The metal now has a full outer shell and a positive charge, the non-metal has gained electrons and will also have a full outer shell but now has a negative charge
- Now as the ions are oppositiely charged, they are attracted to one another, hence an ionic bond
What does the dot and cross model show?
The transferring of electrons
What structure will ionic bonds form?
A lattice structure
What is a lattice structure?
A regular repeating pattern
What is an electrostatic force of attraction?
The force between unlike charges
What ions are bigger than the other in a lattice structure?
The negative ions are bigger than positive ions
What are the properties of ionic compounds?
- They have high melting and boiling points
- They cannot conduct electricity in solid form, they must be in molten or aqueous form
Why do ionic bonds have high melting and boiling points?
Due to the strong electrostatic force of attraction between the positive and negative ions, which requires a lot of energy to overcome
Why can’t ionic bonds conduct electricity in solid form and only molten/aqueous?
- the ions are not free to move in a solid form
- so must be in a molten or aqueous form so that the ions are free to move
- and are able to carry an electrical charge
What does molten mean?
Liquid (has been melted)
What does aqueous mean?
dissolved in water
Why can’t solid ionic compounds conduct electricty?
- The strong electrostatic forces of attraction between oppositely charged ions arranged in a regular lattice structure
- means that they are in fixed positions so are unable to move
- so they can’t carry a charge
- so cannot conduct electricty
Why can molten/aqueous ionic compounds conduct electricty?
- an aqueous ionic compound means the ionic compound has been dissolved into a solution
- Molten means that heat has been applied to melt the ionic compound and overcome the electrostatic forces of attraction
- so the ions are free to move
- so can carry an electrical charge
- so can conduct electricty
What is metallic bonding?
The electrostatic attraction between positively charged metal ions and negatively charged electrons in a lattice structure
Why are metallic bonds arranged in a lattice structure?
Due to the strong electrostatic force of attraction between the positive metal ions and the sea of delocalised electrons
What are the properties of metals? (4)
- High melting and boiling points
- Good conductors of electricty
- Malleable
- Ductile
Why do metals have high melting and boiling points?
Because a lot of energy is required to overcome the strong electrostatic force of attraction
Why are metals good conductors of electricity?
- As the delocalised electrons are free to move
- so can carry an electrical charge
- through the metal structure
What does malleable mean?
Able to be moulded / bent into shape
Why are metals malleable?
Because the regular layers means the layers can slide over each other easily when force is applied
What does ductile mean?
Able to be drawn into wires
What are alloys?
A mixture of 2 or more metals
Why are alloys harder than regular metals?
- Because they are a mix of different metals, which have different shapes and sizes, so distort the regular layers of the pure metal
- So is harder for the layers to slide over each other, so are less malleable, therefore harder
