C3: Structure and Bonding Flashcards
What are the features of solids, liquids and gases?
Solids: Fixed shape and volume and cannot be compressed. Closely packed and vibrate.
Liquids: Fixed volume, can flow and change shape.
Gases: No fixed shape or volume and can be compressed easily. Random motion of particles.
What are the limitations of the simple particle model?
Atoms/molecules/ions are not solids spheres and they have forces between them.
What are the features of giant ionic structures?
- Electrostatic forces of attraction are very strong between oppositely charged ions and act in all directions. Holds ions in a lattice.
- Takes a lot of energy to break bonds meaning it has high melting/boiling points.
- When molten or liquid, ions are free to move to carry electrical charge.
What are the features of simple molecular structures?
Covalent bonds are strong however there are weak intermolecular forces between molecules.
Doesn’t take much energy to break down forces - low melting/boiling points.
Longer chain, larger molecules will have stronger intermolecular forces.
No overall charge so does not conduct electricity.
What are the features of giant covalent structures?
They are huge networks of atoms held together by strong covalent bonds.
Insoluble, high melting/boiling points, hard and don’t conduct electricity (except graphite).
What are the features of graphite in terms of structure and bonding?
• Carbon atoms covalently bonded to 3 others.
• Soft as layers of hexagons can easily slide over each other.
• Conducts electricity because of delocalised electrons between each layer carrying electrical charge.
What are the features of diamond?
Each carbon atom covalenlty bonded to 4 others.
Cannot conduct electricty as all electrons are involved in covalent bonding.
High melting/boiling points.
What is graphene?
A single layer of graphite. It is strong as atoms within layers are very tightly bonded. Excellent conductor of electricity.
What are fullerenes?
Carbon atoms join together to make hollow shaped molecules. Can beused as catalysts, lubricants or for drug delivery. Have large surface area.
What is the structure of metals?
They are giant stuctures arranged in regular layers. Strong electrostatic attraction between negatively charged electrons and positively charged ions bonding the metal together. Delocalised electrons carry electrical charge through the metal.
What are alloys and why are they hard?
Alloys are mixtures of 2 or more elements when at least one is a metal.
They are hard because regular layers in a pure metal are distorted by differently sized particles, meaning it is more difficult for layers to slide over each other.
What is nanoscience?
The study of particles between 1 and 100 nanometres. Have high surface area to volume ratio.
Can be used as catalysts and in cosmetics, delivery of drugs.
