Covalent substances

• What type of bonds do covalent substances contain?

  Covalent bonds
• What can covalent substances be?

  Simple molecules or giant structures
• How are atoms within a molecule held together?

  By very strong covalent bonds
• What is the nature of the forces of attraction between molecules?

  They are very weak
• What is the result of weak intermolecular forces?

  Low melting and boiling points
• How do intermolecular forces compare in strength?

  They are weaker than covalent bonds
• What happens to the melting and boiling points of simple molecular substances?

  They are very low
• What is the relationship between molecular mass and intermolecular forces?

  Larger molecules have stronger forces
• Why do larger molecules require more energy to break intermolecular forces?

  More points of attraction exist
• What states are most molecular substances found in at room temperature?

  Gases or liquids
• How can you identify a substance's physical state?

  By its physical state at room temperature
• How are atoms bonded in giant covalent structures?

  By strong covalent bonds
• What does the presence of many covalent bonds in giant structures imply?

  High energy is needed to break them
• What is the electrical conductivity of giant covalent structures?

  They do not conduct electricity
• What is a characteristic of diamond's structure?

  Very high melting and boiling points
• Why do covalent bonds in diamond require a lot of energy to break?

  They are very strong
• What is the structure of graphite?

  Layers of carbon atoms
• How does graphite conduct electricity?

  Through delocalized electrons
• What is the melting point of graphite?

  Very high
• What is the solubility of covalent substances in water?

  They are usually insoluble
• Why do covalent substances not conduct electricity?

  They lack free-moving charged particles
• What is the characteristic of covalent bonds in diamond?

  They are very strong
• What is the structure of diamond?

  Three-dimensional lattice structure
• How do covalent bonds in diamond affect its properties?

  They give it high hardness and melting point
• What is the bonding in graphite?

  Layered structure with weak forces
• Why is graphite used in pencils?

  It can easily slide between layers
• How do the properties of diamond and graphite differ?

  Diamond is hard; graphite is soft
• What is the main component of diamond and graphite?

  Carbon atoms
• What is the significance of covalent bonds in diamond's structure?

  They create a rigid lattice
• How do covalent bonds affect the melting point of diamond?

  They result in a very high melting point
• What is the physical state of diamond at room temperature?

  Solid
• Why do covalent substances have low melting points?

  Weak intermolecular forces require less energy
• What is the relationship between covalent bonds and electrical conductivity?

  Covalent bonds do not conduct electricity
• What is the structure of covalent substances at room temperature?

  They can be gases or liquids
• What is the significance of the strong covalent bonds in diamond?

  They contribute to its hardness
• How do covalent bonds in diamond affect its melting point?

  They result in a very high melting point
• What is the bonding in graphite?

  Layered structure with weak forces
• Why is graphite used in pencils?

  It can easily slide between layers
• How do the properties of diamond and graphite differ?

  Diamond is hard; graphite is soft
• What is the main component of diamond and graphite?

  Carbon atoms