periodic table

• An atom is the smallest particle of an element
• the periodic table is arranged by the number of protons
• Isotopes are atoms with the same number of protons but different number of neutrons
• stable: having a full electron shell
• 1st shell- max 2 electrons

  2nd shell- max 8 electrons

  3rd shell- max 8 electrons
• elements are organized on the table according to their atomic number
• group 1, the alkali metals
• group 1 can form oxides and hydroxides that are alkaline
• group 1 metals are more reactive that group 2 metals
• group 1

  • density increases as you go down the group
  • melting and boiling points decrease as you go down the group
• group 2, the alkaline earth metals
• When alkali metals are burnt in the air, they produce metal oxides
• Group 1 metals can react with halogens (group 7 elements) to produce halides
• group 2

  their density, melting and boiling points are higher than group 1 metals.
• group 2 metals are less reactive than group 1
• Lithium can be used in batteries and medicine for mental disorder
• Sodium can be used in street lamps, help transfer heat in a nuclear reactor.
• Sodium hydroxide has a wide range of uses like baking, cleaning and food processing
• Potassium can be used as fertilizers, can control the water content and pressure of our blood and send electrical impulses along our nerve cells
• Can form oxides and hydroxides that dissolve slightly in water to make alkaline solution.
• Calcium is important for bones and teeth
• Alkaline earth metals

  Beryllium

  • Combines with aluminum, silicon and oxygen to make a mineral called beryl
  • Combined with other metals to make alloys
• Alkaline earth metals

  Magnesium is used in fireworks to make bright white light
• Alkaline earth metals

  Magnesium is used to make strong and lightweight alloys
• Alkaline earth metals

  Magnesium is used in green plants to make chlorophyll which enables them to trap sunlight to perform photosynthesis
• Alkaline earth metals

  Magnesium is needed in healthy formation of bones and teeth
• Alkaline earth metals

  Calcium is useful in baking powder, bleaching powder, medicines and plastics
• Alkaline earth metals

  Calcium is also needed for healthy formation of bones and teeth
• Alkaline earth metals

  Calcium is responsible for the contraction of our muscles
• The reactivity decreases as you go down the group
• When halogens meet water:

  Fluorine results in a vigorous reaction, producing hydrogen fluoride.
• When halogens meet water:

  Chlorine dissolves
• Fluorine is a pale yellow-green poisonous gas that is found in mineral fluorite
• Fluorine is used to:

  • etching glass surfaces
  • prevent tooth decay
  • one of the elements of CFCs
• Chlorine is a yellow-green poisonous gas
• Chlorine is used to:

  • kill bacteria in water supply systems
  • used to manufacture bleach
  • form hydrochloric acid
• Bromine is a red-brown liquid that produces a poisonous, strong- smelling brown vapor at room temp
• Bromine is used for:

  • Used with silver in traditional photography
• Group 8, the noble gases
• Noble Gases are nonmetals