Sunita carries out an experiment to investigate diffusion. she uses water and a food dye to find out how the volume of water used affects the time the dye takes to spread evenly through the water. her prediction is that the more water she uses, the longer the time needed for the dye to spread through it. a) which variable will she change? b) which variable should she measure? c) state two variables that she will need to keep the same? d) how will she ensure her result are reliable? e) draw a suitable result table for sunita?