CHEMISTRY

• MASS NUMBER - NUMBER OF PROTONS AND NEUTRONS ADDED
• ATOMIC NUMBER - NUMBER OF PROTONS(AND ELECTRONS AS PROTONS AND ELECTRONS ARE THE SAME)
• AN ION IS FORMED WHEN

  AN ATOM GAINS OR LOSES AN ELECTRON (BECOMES CHARGED)
• IONIC 


  METAL AND NON METAL
• COVALENT


  NON METAL AND NON METAL
• METALLIC 


  METAL AND METAL
• ALLOY 


  A MIXTURE OF TWO OR MORE ELEMENTS WHERE AT LEAST ONE ELEMENT IS METAL
• LOST 2 ELECTRONS 


  +2
• GAINED 3 ELECTRONS 


  -3
• IONIC COMPOUNDS

  • MADE UP OF GIANT STRUCTURES ARRANGED IN A LATTICE
  • ELECTROSTATIC FORCES ACTING BETWEEN THE OPPOSITELY CHARGED PARTICLES, THIS HOLDS THE LATTICE TOGETHER
  • STRONG BONDS, NEEDS LOTS OF ENERGY TO BREAK
• SOLIDS

  • PARTICLES VIBRATE IN A FIXED POSITION
  • FIXED SHAPE, CANNOT MOVE
  • PARTICLES CLOSE TOGETHER
  • CANNOT BE COMPRESSED AS PARTICLES HAVE NO SPACE TO MOVE
• LIQUIDS

  • FLOWS AND TAKES SHAPE OF THE CONTAINER
  • PARTICLES CAN MOVE AROUND
  • CANNOT BE COMPRESSED AS PARTICLES ARE CLOSE TOGETHER AND HAVE NO SPACE TO MOVE IN TO
• GAS

  • FLOWS AND COMPLETELY FILLS CONTAINER
  • PARTICLES MOVE QUICKLY IN ALL DIRECTIONS
  • CA BE COMPRESSED AS PARTICLES ARE FAR APART, AND HAVE SPACE TO MOVE INTO
• PERIOD - TELLS YOU HOW MANY SHELLS
• GROUP - TELLS YOU HOW MANY ELECTRONS IN THE OUTER SHELL
• MR OF O2


  (16 X 2) = 32
• MR OF CO2


  (1 X 12) + (2 X 16 ) = 12 + 32 = 44
• CONCENTRATION = MASS (g) / VOLUME ( dm3)
• 8 G OF SODIUM HYDROXIDE IS DISSOLVED IN 2 DM3 OF WATER. CALCULATE THE CONCENTRATION OF THE SODIUM HYDROXIDE SOLUTION FORMED.


  CONCENTRATION = MASS / VOLUME

  CONCENTRATION = 8 / 2

  CONCENTRATION = 4 g/dm3
• N=M/MR


  MOLES = MASS / MR
• FIND AMOUNT OF MOLES IN 37g OF Ca(OH)₂


  N = M / MR

  N = 37 / MR

  MR = ( 40 X 1 ) + ( 16 X 2 ) + ( 1 X 2 ) = 40 + 32 + 2 = 74

  37 / 74 = 0.5

  MOLES = 0.5 MOL
• OPPOSITELY CHARGED IONS ARE ATTRACTED TO EACHOTHER BY STONG ELECTROSTATIC FORCES, FORMING IONIC BONDS
• SALT - SODIUM CHLORIDE, COMPOUND OF A METAL AND NON METAL, MADE OF POSITIVE SODIUM IONS AND NEGETICE CHLORIDE IONS
• GIANT IONIC LATTICES - WHEN OPPOSITELY CHARGED IONS ATTRACT AND FORM SOLID STRUCTURES
• Dot and cross diagram

  Models the transfer of electrons from metal atoms to non-metal atoms
• MORE REACTIVE METALS CAN DISPLACE LESS REACTIVE METALS- DISPLACEMNET REACTIONS
• IRON + COPPER SULFATE --> IRON SULFATE + COPPER

  IRON IS MORE REACTIVE
• HALF EQUATIONS SHOW WHAT HAPPENS TO EACH REACTANT
• FE --> FE²⁺ + 2e-
• METAL + ACID --> SALT + HYDROGEN
• SQUEAKY POP - HYDROGEN IS PRESENT
• IF A LIT SPLINT GOES OUT , CO2 IS PRESENT
• IF THE SPLINT RELIGHTS , OXYGEN IS PRESENT
• ACID + ALKALI --> SALT + WATER
• ACID + BASE --> SALT + WATER
• ACID + ALKALI, NEUTRALISATION REACTION
• COVALENT BOND FORMED WHEN 2 ATOMS SHARE ELECTRONS