Biological specimens have been preserved in alcohol and formalin for many years.This could damage the specimen and change the colour of the fluid.Engineered fluids are now used as a substitute for formalin as it is a more sustainable medium..Novec fluids which are low in toxicity are also used. read more
Chromium forms compounds of various colors. (The word chromium comes from the Greek khroma, meaning "color"; see Figure 3.9.) Sodium dichromate is the most important commercial chromium compound, from which many other chromium compounds are manufactured. It is a bright orange, crystalline substance. read more
However, a structural formula also shows how the atoms in a compound are bonded together. Both formulas identify the types of atoms in a particular compound. However, a structural formula also shows how many atoms of each type are in a compound. Both formulas show the location of each valence electron in a particular compound. read more