Use the Interactive Periodic Table to answer the following questions about ionization energy. I. What is the first ionization energy (IE1) of sulfur (atomic number 16)? II. Write the expressions for the successive ionization energies of S(IE1 to IE7) ? III. Plot the successive ionization energies of S(IE1 to IE7). IV. What trend is seen in this plot? How do you explain the change in slope associated with the IE7 ?