Introduction
Website for questions 1-3
http://www.chem4kids.com/files/matter_intro.html
Website for question 4-7
http://education.nationalgeographic.com/education/encyclopedia/water-cycle/?ar_a=1
Website for questions 8-11
http://www.ducksters.com/science/electricity_102.php
Wesbite for questions 12-14
http://www.ducksters.com/science/sight_and_the_eye.php
Website for questions 15-16
http://www.ducksters.com/science/hearing_and_the_ear.php