Class 8 Cbse Ncert Revision Question's1) When a ball pen refill is rubbed vigorously against polythene, it attractssmall pieces of paper. What makes the refill attract paper?2) Write the use of an electroscope. 3) Explain the purification of copper using electrolysis with the help of anelectric circuit. 4) Write any two uses of electrolysis. 5) Why are multiple images formed when two mirrors are placed at rightangles to each other?6) Why should we not stand under a tree when there is thunder andlightning?7) We electroplate metals with chromium to make car parts, bath taps, kitchen gas burners etc. Why is chromium itself not used for makingthese materials?8) Describe the chemical effect of current on water with the help of adiagram. 9)Paheli wants to deposit silver on an iron spoon. She took silver nitrate(AgNO3) solution in a beaker and set up a simple circuit forelectroplating. Which terminal of the battery should the spoon beconnected to? What material should the other electrode be made of?10) An electric current is passed through a conducting solution. List anythree possible observations. 11) What happens to light when it gets dispersed? Give an example. 12) How are the eyes of the day birds different from night birds?