chemistry

chemistry

1. atomic number

   • number of protons
     • bottom

2. mass number

   • total of protons and neutrons
     • top

3. calculating maximum mass

   • mass = MR x MOLES

4. diamond + graphite

   • graphite
     • covalent bonds-strong
       • alot of energy needed to seperate
         • high melt + boiling point
     • each carbon atom is only covalently bonded to three other carbon atoms,
       • CARBON
         • CARBON
         • CARBON
         • CARBON
     • LAYERS OF carbon atoms
       • weak forces betweene each layer
         • layers slippery
     • delocalised electrons
       • move between layers
         • carry a charge
           • conduct electricity
   • DIAMOND
     • each caron atom is covalently bonded to 4 carbon atoms
       • CARBON
         • CARBON
         • CARBON
         • CARBON
         • CARBON
     • covalent bonding.
       • hard to break
     • DOESNT CONDUCT ELECTRICITY

5. POLYMERS

   • smaller molecules join together, end to end.
     • SMALLER MOLECULES=monomers
     • lots of monomer molecules → a polymer molecule

6. development of periodic table

   • mendaleev
     • He put the known elements in order of relative atomic mass but LEFT GAPS for undiscovered elements
       • atomic mass left out
         • similar properties
   • newlands
     • He arranged the known elements in order of their atomic masses.

7. atomic strucutre

   • nucleus
     • protons + neutrons
       • oppositely charged
   • electrons on shells

8. isotopes

   • same number of protons but different numbers of neutron
     • different mass numbers