Question

Which of the following can be repeatedly softened on heating? (i) Polystyrene (ii) Melamine (iii) Polyesters (iv) Polyethylene (v) Neoprene

• A. (i) and (iii)
• B. (i) and (iv)
• C. (iii), (iv) and (v)
• D. (ii) and (iv)

Hint:

Thermoplastics can be reshaped repeatedly, thermosetting plastics cannot.

Answer 1

The Correct Option is B

Step 1: Thermoplastics soften repeatedly on heating.
Step 2: Polystyrene and polyethylene are thermoplastics.
Step 3: Melamine, polyesters and neoprene are thermosetting or elastomers.