Topic 2: Bonding, structure and Properties of Matter Flashcards
What is the nature of ions in ionic bonding?
Ions are oppositely charged
What is covalent bonding?
Atoms share pairs of electrons
What is metallic bonding?
Atoms which share delocalised electrons
What does ionic bonding occur between?
Metals combined with non-metals
Where does covalent bonding occur?
Non-metal elements
Where does metallic bonding occur?
Metallic elements and alloys
Explain what happens in ionic bonding [4]
- A metal atom reacts with a non-metal atom
- Electrons in the outer shell of the metal are transferred
- Metal atoms lose electrons to become positively charged ions
- Non-metal atoms gain electrons to become negatively charged ions
What is the diagram called for ionic bonding?
Dot and cross diagrams
What is the name of the structure for ionic compounds?
Giant ionic lattice
What hold the ions together in a giant ionic lattice?
Strong electrostatic forces of attraction
Why do ionic compounds have high melting and boiling points? [2]
- Numerous strong ionic bonds
- Large amount of energy is needed to break them apart
Why can ionic compounds conduct electricity when liquid? [2]
- Ions are free to move
- Can carry an electrical charge
Why can’t ionic compounds conduct electricity when solid? [2]
- Ions are held in place
- So can’t carry an electrical charge
Why are ionic compounds brittle?
When they are broken apart, opposite charges in the lattice repel each other and break the lattice
Why are the limitations of using a 3D model to show an ionic compound?
Only shows the outer layer of the compound
Why are the limitations of using a ball and stick model to show an ionic compound? [2]
- Relative sizes of the ions not shown
- No gaps between ions irl
Why are the limitations of using a dot and cross diagram to show an ionic compound?
Doesn’t show the structure of the compound
Why are the limitations of using a dot and cross diagram to show covalent bonding?
Don’t show the relative sizes of the atoms
Why are the limitations of using a displayed formula to show covalent bonding?
Don’t show the 3D structure of the molecule
Why are the limitations of using a 3D model to show covalent bonding?
Don’t show where the electrons have come from
Why do simple molecules have low melting and boiling points? [2]
- The covalent bonds are not broken
- However, the forces holding neighbouring particles together are weak and easily overcome
Why don’t simple molecules conduct electricity?
They are not charged, so there are no free electrons or ions
What kind of structure is diamond, graphite and silicon dioxide?
Giant covalent structures
Why does diamond have a high meting and boiling point? [2]
- Strong covalent bonds
- Much energy needed to break them
Why can’t diamond conduct electricity? [2]
- Doesn’t contain charged particles
- So can’t carry an electrical charge
How many bonds does diamond make per carbon?
4