CHEMICAL CHANGES

• ionic = metal + nonmetal
• covalent = nonmetal + nonmetal
• ionic bonds : ionic bonds are formed between metals and non-metals as the transfer of electrons from metal to non-metal allows both to have fully-filled valence shells and to achieve a stable electronic configuration.
• covalent bonds: covalent bonds are formed between non-metal and non-metal as atoms share their valence electrons so that both get a full valence shell and achieve a stable electronic configuration
• covalent bond = don't cross product
• ionic bond = cross product
• heat = thermal decomposition
• oxygen = respiration,combustion
• light=photosynthese, x-ray imaging
• electricity = electrolysis, electroplating
• thermal decomposition, photosynthesis, x-ray imaging, electrolysis, electroplating = decomposition
• decomposition = a single compound breaks down into two or more simple substances

  A-> b+c+
• combination = two or more substances combine to form a single new compound
• observations:

  -> colour change

  -> formation of an insoluble solid (precipitate)

  -> formation of gas

  -> transfer of light energy or heat
• oxygen

  02
• hydrogen gas

  h2
• nitrogen gas

  N2
• fluorine

  f2
• chlorine

  cl2
• carbon dioxide

  co2
• carbon monoxide

  co
• nitrogen dioxide

  no2
• nitrogen monoxide


  no
• sulfur dioxide

  so2
• methane

  ch4
• ammonium

  NH4+
• ammonia

  NH3
• hydrochloric acid

  HCl
• sulfuric acid

  H2SO4
• phosphoric acid

  H3PO4
• nitric acid

  HNO3
• sodium hydroxide

  NaOH
• potassium hydroxide

  KOH
• ammonium hydroxide

  NH4OH
• magnesium hydroxide

  Mg(OH)2
• calcium hydroxide

  Ca(OH)2
• oxide


  o2-
• fluoride

  f-
• chloride


  cl-
• nitride

  n3-