More notes

• 1 molecule = 6.02 multiplied by 10 to the power of 23
• Percentage yield = actual yield/predicted yield multiplied by 100
• Percentage purity = g of pure product/g of impure product multiplied by 100
• Some isotopes decay meaning that they are radioactive. They change their atomic structure and become a new element
• Uses of radiation:

  Check for leaking pipes

  Cancer treatment

  Finding the age of old remains
• Electrolysis is the decomposition of an ionic compound
• Ionic compound must be molten or aqueous state to conduct electricity
• Inert electrons dont dissolve but they do conduct electricity
• In electrolysis the molecules will accumalate and attach to its terminal
• Half-equation are ionic equations showing the seperate oxidation and reduction steps in redox reactions
• Preferential discharge is when the least reactive element is discharged first before the more reactive substance
• The no. of charges on an element relate to the elements group no.
• Oxidation is whereby oxygen is added to a compound
• Oxidation:

  Involves the loss of electrons

  The oxidation state of an element is increased
• Reduction is a reaction in which oxygen is removed from a compound
• Reduction:

  Electrons are gained

  The oxidation state of an element is decreased