Covalent Network Solids Full Summary

Question 1

Type Of Particles:

Answer 1

Atoms

Question 2

Forces Of Attraction Between Particles:

Answer 2

• Covalent bonds
• Large network of atoms covalently bonded to each other, either in a linear 1D chain (eg, plastic, rubber), 2D layers (eg, graphite in pencils) or 3D networks (eg, diamonds)

Question 3

Electrical Conductivity:

Answer 3

• 1D chains: There are no charged particles that are freely moving, so therefore it doesn’t conduct electricity
• 2D layers: Contains freely moving electrons between the layers, so therefore they can conduct electricity
• 3D networks: No charged particles that are freely moving, each atom’s electrons are involved in covalent bonding, so therefore it doesn’t conduct electricity

Question 4

Melting/Boiling Point:

Answer 4

• 1D chains: The longer the chain, the more sites are available for intermolecular forces between the chains, so therefore more energy is required to break these forces, resulting in higher melting/boiling points
• 2D layers: 2D layers have very strong bonds and therefore require a lot of energy to break, which means that they have a high melting/boiling point
• 3D networks: Requires breaking the 3D networks of strong covalent bonds and therefore a lot of energy is required to break them, so therefore they have high melting/boiling points

Question 5

Solubility In Water:

Answer 5

Insoluble, because all covalent network solids are non-polar

Question 6

Toughness:

Answer 6

• 1D chains: The chains can slide over each other easily, so they are soft and flexible
• 2D layers: The layers can slide over each other without disrupting the bonds, so they are soft and slippery
• 3D networks: Atoms are held in firm 3D arrays/networks, so they are strong and rigid