Classify each of the following as each as belonging to a per…

Classify each of the following as each as belonging to a period, a group or is not found in the periodic table.  An answer may be used once, more than once or not at all.  However, there is only one correct answer for each. [a1]  Vertical arrangement of elements in the periodic table [a2]  Horizontal arrangement of elements in the periodic table [a3] Elements with similar chemical properties [a4]  Mass number