Small crystals of purple $\text{KMnO}_4$ ($M_r = 158$) and orange $\text{K}_2\text{Cr}_2\text{O}_7$ ($M_r = 294$) were each placed at the middle of separate petri dishes containing agar jelly. They were then left in the same conditions. After a period of time, the colour of each substance had spread out, as shown. The arrow lengths show the relative distances moved by particles of each substance. Which statement is correct?
- ADiffusion is faster in dish 1 because the mass of the particles is greater.
- BDiffusion is faster in dish 2 because the mass of the particles is greater.
- CDiffusion is slower in dish 1 because the mass of the particles is smaller.
- DDiffusion is slower in dish 2 because the mass of the particles is greater.