Topic 2

Cards (33)

  • When are Ions formed
    when atoms gain or lose electrons
  • which groups for ions
    group 1&7
    group 2&6
  • Ionic Bonding

    - metal and non-metal
    - transfer of electrons
    - form ionic bonds
    - metal forms a positive ion
    - non-metal forms a negative ion
    - strong electrostatic forces
  • Ionic compounds

    - giant ionic lattice structure.
    - form a closely packed lattice structure.
  • Covalent bonds

    - non-metal and non-metal
    - electrons share bonds.
    - form covalent bonds
    - draw through dot and cross diagrams
  • Hydrogen H

    - 1 electron
    - form single covalent bonds
  • Chlorine Cl

    - needs 1 extra electron
    - 2 chlorine atoms can share an electron each
    - form a single covalent bond
  • Oxygen O

    - needs 2 more electrons
    - 2 atoms share 2 electrons each.
    - double covalent bond
  • Nitrogen N

    - need 3 more electrons each
    - 2 N atoms share 3 electrons each
    - triple bond
  • Methane CH4

    - carbon has 4 outer electrons
    - forms 4 covalent bonds with hydrogen
  • Water H2O

    - oxygen has 6 outer electrons.
    - 2 hydrogen atoms can bond to form 2 covalent bonds
  • Hydrogen Chloride HCl

    - Both atoms only need 1 extra electron
    - 1 covalent bond
  • Properties of simple molecular sub
    - held together by strong covalent bonds
    - weak intermolecular forces
    - very low melting and boiling points
    - mostly gases or liquids at room temp
    - don't conduct electricity
  • Polymers

    large compound formed from combinations of many monomers with repeating sections.
  • Silicon dioxide

    - silica
    - sand is made of this
  • Diamond

    - really hard
    - strong covalent bonds
    - very high melting bonds
    - doesn't conduct electricity
  • Diamond structure

    Each carbon atom forms four covalent bonds in a very rigid giant covalent structure
  • Graphite

    - sheets of hexagons
    - no covalent bonds between layers
    - soft
    - slippery
    - ideal for lubrication
    - Hight melting point
    - free electrons - can conduct electricity
  • Graphite structure

    each carbon atoms forms 3 covalent bonds to create layers of hexagons.
    -each carbon atom also has 1 delocalised electron.
  • Fullerenes

    - shaped like hollow balls
    - carbon arranged in hexagons
    - can be used to 'cage' other molecules
    - can be used to deliver a drug into body
    - huge surface area - great industrial catalysts.
  • Fullerenes structure

    can for nanotubes - can conduct electricity and heat
  • Metallic Bonding

    - electrons in outer shell are delocalised electrons
    - strong forces of attraction
    - This bonding is very strong
  • Metals

    - mostly solid at room temperature.
    - High MP and BP
    - good conductors of heat and electricity
    - most are malleable
  • Alloys

    - mixtures of two or more metals
    - harder/stronger
    - different sized atoms - distort layers - harder to move
  • States of Matter: Solid, liquid, gas
  • solid

    Definite shape and volume
  • Liquid

    A state of matter that has no definite shape but has a definite volume.
  • gas

    A state of matter with no definite shape or volume
  • changing state
  • Nanoparticles

    medicine
    electronics
    cosmetics
    sun creams
    deodorants
    catalysts
  • NanoMedicine

    Area of biomedical research that seeks to use tools from the field of nanotechnology to improve health.
    Use these (like fullerenes) to deliver drugs right into cells.
  • Effects of Nanoparticles on health
    1) The way they affect the body isn't fully understood
    2) Some people are worried that products containing them have been made available before the effects on human health have been investigated properly
    3) We don't know what the long-term impacts on health will be
    4) Many people believe that products containing nanoparticles should be clearly labelled
  • Nanoparticles example use: sun creams

    - better materials to protect skin
    - give better skin coverage
    - not clear whether they can get into your body or if they will damage cells
    - also possible when washed away they could damage the environment.