BONDING

• what are the three types of strong chemical bonds?


  - ionic

  - covalent

  - metallic
• what kind of particles does ionic bonding include?


  oppositely charged ions
• what kind of particles does covalent bonding include?


  atoms which share pairs of electrons
• what kind of particles does metallic bonding include?


  atoms which share delocalized electrons
• where does ionic bonding occur?


  between metals and non-metals
• where does covalent bonding occur?


  between two non-metals
• where does metallic bonding occur?


  between two metals
• when happens during ionic bonding?


  - electrons in the outer shell of the metal atom are transferred

  - metals becomes positive, non-metals become negative
• what is an ionic compound?


  a giant structure of ions held together by strong electrostatic forces of attraction between oppositely charged ions
• what are the advantages and disadvantages of a dot and cross diagram?

  + shows how ionic compounds are formed

  - don't show size, structure or arrangement

  
• what are advantages and disadvantages of a ball and stick diagram?


  + shows arrangement

  - isn't to scale

  - there aren't actually gaps
• what are advantages and disadvantages of a 3D diagram?


  + shows relative sizes and patterns

  - only shows outer layers
• what is a covalent compound?


  a chemical compound formed by the sharing of electrons
• what are examples of small molecules?


  - hydrogen

  - chlorine

  - oxygen

  - nitrogen

  - hydrogen chloride

  - water

  - ammonia

  - methane
• what is an example of covalently bonded substances that has very large molecules?


  polymers
• what are the three states of matter?


  solid, liquid, gas
• what are limitations of the particle theory?


  - doesn't show forces between particles

  - particles are represented by solid inelastic spheres
• what are the properties of ionic compounds?

  - high melting and boiling points

  - conduct electricity when molten or dissolved
• what are the properties of small molecules?


  - low melting and boiling points

  - don't conduct electricity
• what are examples of giant covalent structures?


  - diamond

  - graphite

  - silicon dioxide
• what are properties of pure metals?


  malleable, soft
• why are alloys harder than pure metals?


  they distort the layers of atoms making it hard for the layers to slide
• why are metals good conductors?


  the delocalized electrons carry electrical charge and thermal energy through the metal
• what is the structure of diamond?


  each carbon atom forms four covalent bonds with other carbon atoms
• what are the properties of diamond?


  - very hard

  - very high melting point

  - doesn't conduct electricity
• what is the structure of graphite?


  each carbon atom forms three covalent bonds with three other covalent bonds; one electron from each carbon atom is delocalized
• what are the properties of graphite?


  - soft and slippery

  - conducts electricity

  - high melting point
• what is graphene?


  a single layer of graphite
• what are the properties of graphene?


  - very strong

  - very light

  - electrical conductor
• what are fullerenes?

  molecules of carbona toms with hollow shapes
• what are carbon nanotubes and what are they used for?


  - cylindrical fullerenes with very high length to diameter ratios

  - nanotechnology, electronics, materials
• what does nanoscience refer to?


  structures that are 1-100nm in size
• how big are nanoparticles?


  100-2500nm
• how big are fine particles?


  PM₂․₅
• how big are coarse particles?


  PM₁₀ (1 × 10⁻⁵ to 2.5 × 10⁻⁶)
• what are applications of nanoparticles?


  - medicine

  - electronics

  - cosmetics

  - sunscreen

  - deodorants

  - catalysts
• what are advantages and disadvantages of nanoparticles?


  + huge surface area to volume ratio

  - their effects aren't fully understood

  - might damage cells/the environment
• Ionic bonding


  Electrostatic attraction between positive and negative ions
• Ionic bonding


  • Relatively strong attraction
• How ionic compounds are held together


  1. In a giant lattice

  2. Regular structure that extends in all directions

  3. Electrostatic attraction between positive and negative ions holds the structure together