|Time Frame||IYPT 2018|
|Supplementary Materials||colours of powder final ppt|
Ifrah also spent time exploring how a coloured material is ground to a powder where it experiences amazing colour changes. The problem also encouraged her to investigate how the degree of grinding affects the apparent colour of the powder. As different chemical pigments absorb different wavelengths of light and the colours of particles don’t change from different angles when we observe. Further, grinding the mirror like crystals will make them whiter and rougher than before and when the light hits the small mirror like crystals it is scattered into many directions. Ifrah grew crystals of chemical potassium ferricyanide, copper sulphate and sodium nitrate. She then grounded the crystals into smaller particles and then analyzed them under a microscope for investigating the relationship between the particle size, chemical type and the incident light colour.