Periodic Table

• What are the vertical columns called?

  groups
• What are the rows called?

  Periods
• How are the elements arranged in the modern periodic table?

  By order of increasing atomic number
• Where are the metals on the periodic table?


  Left
• Where are the non metals on the periodic table?


  Right
• What does the group number tell you about an element?

  Number of electrons in the outer most shell
• What does the atomic number tell you about an element?

  Number of protons or the total number of electrons
• What does the period number tell you about an element?

  Number of shells
• Why were Mendeleev's ideas accepted by others?

  Left gaps for undiscovered elements, fitted with his predictions
• How did Mendeleev order the elements?

  Mainly by increasing atomic weight, took account of properties
• Why were early periodic tables incomplete?

  Some elements were unknown, some elements were placed in groups with elements that did not have similar properties