C2 Periodic Table

• what is an element?

  A substance that cannot be broken down into simpler substances by chemical means and are made of only one type of atom.
• In relation to the periodic table, what was happening almost every year in the 19th century?

  chemists were finding new elements almost every year.
• what year did John Newland build on Dalton's ideas?

  1864
• what did John Dalton suggest?

  he arranged the elements in order of their atomic weights

  
  

  these had been measured in various chemical reactions
• how did Newland arrange the known elements?

  in order of mass but noticed that the properties of every eighth element seemed similar.
• who produced the table showing the "law of octaves" ?

  John Newlands
• when did Mendeleev have a breakthrough?

  1869
• who was Dmitri Mendeleev?

  a Russian chemist who created the periodic table in 1869
• how did Mendeleev order his table?

  By increasing atomic mass, and leaving gaps for unfound elements (which resulted in helping him predict / find them)
• what is a group on the periodic table?

  the vertical columns
• what is a period on the periodic table?

  the horizontal rows
• what is group 1 on the periodic table called?

  the alkali metals
• what is group 2 and the periodic table called?

  the alkaline earth metals
• what is group 3 and the periodic table called?

  the transition metals
• what is group 7 and the periodic table called?

  the halogens
• what is group 7 and the periodic table called?

  the noble gases
• what happens to reactivity as the periodic table goes down?

  it decreases
• why does reactivity decrease as you go down the periodic table?

  because the atomic mass of the halogens increases.