Bonding

• why do atoms react

  in order to obtain a full outer shell
• how do metals and non-metals react

  metals loose electrons to form positively charged ions

  non-metals gain electrons to form negatively charged ions
• what group of elements of the periodic table doesn't react and why

  group 0 elements as they already have a full outer shell
• what are ionic bonds


  electrostatic attraction between oppositely charged ions
• what are covalent bonds 


  an electrostatic attraction between a shared pair of electrons
• which section of the periodic table is only involved in covalent bonding

  non-metals
• what is a double bond

  it is a covalent bond that is formed by sharing 4 electrons (2 pairs) between 2 atoms
• which are the strongest bonds

  covalent bonds
• give 3 properties of simple covalent molecules and explain them

  1 low melting points and boiling points

  as it doesn't require a lot of energy to break the weak intermolecular forces

  2 can only be liquid or solid when the temperature is low enough

  so it can pull the molecule together through the intermolecular forces

  3 don't conduct electricity

  as there is no charged particles or ions and there is no free electrons to carry the flow of charge
• what are allotropes

  different forms of the same element
• what are the 5 allotropes of carbon

  diamond, graphite, graphene, buckminster-fullerene and nanotubes
• how many carbon atoms is each single carbon atom in diamond bonded to

  each carbon atom is bonded to 4 other carbon atoms
• what are the 3 properties of diamonds

  1 high melting and boiling points

  2 very hard

  3 doesn't conduct electricity
• how many carbon atoms is each carbon atom in graphite, graphene and the fullerenes bonded to

  each carbon atom is bonded with 3 other carbon atoms
• why is there a delocalised electron in graphite

  as the C atoms are only bonding to 3 other atoms not 4 so there is a spare one
• what are the 3 properties of graphite

  1 high melting and boiling points

  2 conducts electricity

  3 slippery
• how many layers of graphite makes up graphene

  1 single layer
• what are the 4 properties of graphene

  1 high melting and boiling points

  2 strong

  3 conducts electricity

  4 almost transparent
• what is the nickname of the fullerene Buckminster-fullerene

  Bucky balls
• how many carbon atoms are bonded in a bucky ball

  60 carbon atoms
• what are 2 uses of bucky balls

  1 lubricants

  2 to deliver medical drugs directly to cells
• what is the structure of nanotubes

  they are sheets of graphene rolled into a tube
• what are some uses of nanotubes

  to reinforce sports equipment
• what section of the periodic table is only involved in metallic bonding

  metals, to form positive metal ions by loosing electrons
• what is metallic bonding

  the electrostatic attraction between positive metal ions and a sea of delocalised electrons
• name 3 properties of metallic bonds and explain

  1 high melting and boiling points

  as there is large amounts of energy needed to overcome the electrostatic attraction

  2 conducts electricity

  as the delocalised electrons can move through the structure carrying the flow of charge

  3 malleable and ductile

  as the atoms have the ability to move over each other into new positions without breaking the metallic bonds
• what are nanoparticles 


  a particle between 1nm and 100nm across
• what are the steps to calculating the surface area to volume ratio

  1 calculate the surface area: 6 x(length x length)

  2 calculate the volume: length x length x length

  3 calculate the ratio: area/volume
• What does the period tell us about an element

  the number of shells it has
• what does the group tell us about an element

  how many electrons are in its outer shell
• name 6 properties of metals 


  shiny

  high melting and boiling points

  solid at room temperature

  malleable

  ductile

  good conductors
• name 6 properties of non-metals 


  dull

  low melting and boiling points

  half are solids, half are gas at room temperature

  brittle

  non-ductile

  poor conductors (insulators)
• give 3 properties of ionic compounds and explain


  1 high melting and boiling points as it requires a lot of energy to break the strong ionic bonds

  2 conducts electricity (as a gas or liquid) as the ions can move freely and carry the flow of charge

  3 soluble in water as the polar water molecules can separate and surround the ions, breaking the ionic lattice
• name 2 properties of nanotubes

  1 very strong

  2 conduct electricity
• name 2 properties of buckyballs 


  1 conducts electricity

  2 very strong
• what are 2 properties of nanoparticles and explain them

  1 highly reactive as they have a large SA:V ratio, meaning in a small amount of the material they have a large surface area for interactions

  2 strong due to its small size allowing them to be tightly compact
• what are the uses of nanoparticles and explain how their properties relate to them


  1 catalysts as their high SA:V ratio increases their reactivity

  2 drug delivery to cells as their SA:V ratio and small size allows them to interact with cells
• what are risks of nanoparticles 


  • they could be breathed in or absorbed by the skin (as they are so small) which can be toxic to your body causing damage
  • may be released into the environment and interact + damage ecosystems
• how did Mendeleev arrange the periodic table 


  by atomic weight and he grouped elements with similar properties; and he left spaces for undiscovered elements and predicted the properties of some elements