Levigation is the process of grinding an insoluble substance to a fine powder, while wet.
The material is introduced into the mill together with water, in which the powdered substance remains suspended, and flows from the mill as a turbid liquid or thin paste, according to the amount of water employed.
There is no loss of material as dust, nor injury or annoyance to the workmen. Further, any soluble impurities in the substance are dissolved, and the product thereby purified.
The greatest advantage of this process is the facility it affords for the subsequent separation of the product into various grades of fineness, because of the slower subsidence of the finer particles from suspension.
Section-1: General Science - Chemistry Question - 7
The element that was formally discovered by Scottish physician Daniel Rutherford was:
Nitrogen is formally considered to have been discovered by Scottish physician Daniel Rutherford in 1772, who called it noxious air.
Though he did not recognize it as an entirely different chemical substance, he clearly distinguished it from "fixed air".
The fact that there was a component of air that does not support combustion was clear to Rutherford. Nitrogen was also studied at about the same time by Carl Wilhelm Scheele, Henry Cavendish, and Joseph Priestley, who referred to it as burnt air.
Section-1: General Science - Chemistry Question - 8
Which of the following element is not an isotope of carbon?