Chemistry bonding and property of substances

• What happens to metal atoms during ionic bond formation?

  They lose electrons to become positive ions
• What do non-metal atoms do during ionic bond formation?

  They gain electrons to become negative ions
• Why do ions have full outer electron shells?

  Because they gain or lose electrons
• What is the charge of Group 1 ions?

  1+
• What is the charge of Group 2 ions?

  2+
• What is the charge of Group 6 ions?

  2-
• What is the charge of Group 7 ions?

  1-
• How do you work out the formula of an ionic compound?

  Using the formulae of the ions in it
• What does a dot and cross diagram represent?

  Electron transfer during ionic compound formation

  
• What is a giant ionic lattice made of?

  Positive and negative ions
• What holds the ions together in a giant ionic lattice?

  Strong electrostatic forces of attraction
• How is sodium chloride represented in diagrams?

  Ball & stick model or 3D diagram

  
• What is a limitation of using diagrams for giant ionic structures?

  They may oversimplify complex structures
• Why do ionic compounds have high melting and boiling points?

  Strong electrostatic attractions require much energy
• Why don’t ionic compounds conduct electricity when solid?

  Because the ions are in fixed positions
• When do ionic compounds conduct electricity?

  When molten or dissolved in water
• What defines a covalent bond?

  A shared pair of electrons between non-metals
• What do most covalent substances consist of?

  Small molecules with a few atoms
• What type of forces exist between small molecules?

  Weak intermolecular forces of attraction
• How can you recognize common small molecules?

  From their chemical formula
• What are polymers in terms of covalent substances?

  Simple covalent substances with large molecules
• What is a double bond in covalent bonding?

  Sharing two pairs of electrons
• What is a triple bond in covalent bonding?

  Sharing three pairs of electrons
• Which molecules can be represented with dot and cross diagrams?

  Hydrogen, chlorine, oxygen, nitrogen, etc.
• How are covalent bonds represented in diagrams?

  With lines for single and double bonds
• What is a limitation of using diagrams to represent molecules?

  They may not show all interactions accurately
• What state are simple covalent substances usually in at room temperature?

  Gases or liquids
• What happens when simple covalent substances melt or boil?

  Intermolecular forces are broken
• How much energy is required to break weak intermolecular forces?

  Little energy is required
• How do larger molecules affect intermolecular forces?

  They have stronger intermolecular forces
• Why don’t simple covalent substances conduct electricity?

  They lack free-moving charged particles
• What are nanoparticles made of?

  A few hundred atoms
• What is the size range of nanoparticles?

  1 to 100 nm in diameter
• Why do nanomaterials have different properties than bulk materials?

  High surface area to volume ratio
• What does the high surface area to volume ratio mean for nanomaterials?

  Smaller quantities are needed to be effective
• What are some applications of nanoparticles?

  Medicine, electronics, cosmetics, etc.
• Why is research on new applications for nanomaterials important?

  To explore potential benefits and risks
• What are the risks associated with nanoparticles?

  Insufficient evidence on long-term effects
• What is the structure of graphene?

  A single layer of graphite
• Why is graphene hard to break?

  Strong covalent bonds between carbon atoms