C4 - Chemical Patterns

C4 - Chemical Patterns

1. Atoms

   • Nucleus
     • Protons
     • Neutrons
   • Electrons
     • Same number of protons and electrons

2. Equations must be balanced

3. Line Spectrums

   • Lithium = Red
   • Sodium = Yellow
   • Potassium = Purple
   • Line spectrums can identify new elements
   • Different elements emit different wavelengths of light

4. History of the Periodic Table

   • Dobereiner
     • Triads
   • Newland
     • Law of octaves
   • Mendeleev
     • order of atomic mass
     • Left gaps and predicted new elements

5. Modern Periodic Table

   • Puts elements with similar properties together
   • Increasing proton number

6. Electron Shells

   • occupy shells
   • The lowest energy levels are filled first
   • 1st shell = 2
   • 2nd = 8th
   • If the outer shell isnt full the atom is more reactive

7. Ionic Bonding

   • Ions are made when atoms gain or lose electrons
     • They do this to get a full outer shell
       • a shell with 1 electron with try and get rid of it
       • a nearly full shell is trying to get another electron
   • Oppositely charged ions are attracted to each other
     • Ionic compounds form a regular lattice
     • conduct electricity when molten or dissolved
       • Ions are able to move

8. The charges in an Ionic Compound add up to zero e.g. Li+ and F- = LiF

   • e.g. Ca2+ and Cl- = CaCl2
   • e.g. Fe3+ and SO4 2- = Fe2(SO4)3
   • Find the charge on the oxide ion in K2O if the charge on the potassium ion is 1+. = K is (2 x 1+)= 2+. So... oxygen ion must be 2-

9. Group 1 - The Alkali Metals

   • one outer shell electron = very reactive
   • Tarnishes in air quickley
   • the bigger the element the more reactive - outer shell further from nucleus
   • as you go down : lower melting and boiling point
   • Reacts with cold water to produce hydrogen gas
   • Reacts with chlorine to form salts

10. Group 7 - Halogens

11. Hazard Symbols

Images and files in the map