2.4 periodic table

• The elements in the periodic table are arranged in...

  rows in order of increasing atomic number
• Chemists use what to organise the elements into colums?

  number of electrons in outer shell
• The horizontal rows are also known as ?

  Periods
• The vertical columns are also known as ?

  Colums
• Main group elements are groups...

  1, 2 and 13 to 18
• Transition metals are in groups...

  3 to 12
• What is it called when elements are arranged into vertical columns?

  Groups
• What does the group number determine?

  The number of valence electrons in an atom of an element
• What group are the noble gases in?

  Group 18
• What are the horizontal rows in the periodic table called?

  Periods
• The period an element is located in is equal to what?

  The number of occupied electron shells in the elements atom.
• When an element is in a certain block this indicates....

  that it has the same type of subshell as the highest energy subshell as the other elements in that group
• What are the 4 types of energy subshells?


  s, d, p, f.
• Elements use that has become unsustainable are?

  Critical elements
• To ensure critical elements are available for future generations...


  methods of recycling and recovery must be developed.