question_answer

  Show diagrammatically how water is purified in the waterworks system and list the processes involved.

Answer:

                  (i) Curiosity, good analytical skills.                  (1) (ii) The tiny particles are particles of dust and smoke.                                                              (1) (iii) Because these are too small to be seen by naked eyes.                                                      (1) (iv) Tyndall effect.                                          (1) (v) Blue colour of sky or blue iris in an eye. (1)