4. a) Outline with diagram the molecular structures of linear, branched, and cross-linked polymers. [5 marks] b) Distinguish between the characteristics of Polymer P and Polymer Q shown in Figure Q4(b)(i) and Figure Q4(b)(ii). [16 marks] Melts Reforms Soft Soft Figure Q4(b)(i): Polymer P Soft Soft Figure Q4(b)(i): Polymer P Melts Reforms Hard Soft Figure Q4(b)(ii): Polymer Q c) Based on the answer in Q4(b), determine with ONE (1) reason the recycle-ability of Polymer P and Polymer Q. [4 marks]