**Pi**(π), the 16th letter of the Greek alphabet, is used to represent the most widely known mathematical constant.

**Pi**is an irrational

**number**, which means that it is a real

**number**with nonrepeating decimal expansion. It cannot be represented by an integer ratio and goes on forever, otherwise known as an infinite decimal.

Then, what does PI mean in chemistry?

The isoelectric point (

**pI**, pH(I), IEP),**is the**pH at which a particular molecule carries no net electrical charge or is electrically neutral in the statistical**mean**. The standard nomenclature to represent the isoelectric point is pH(I), although**pI**is also commonly seen, and is used in this article for brevity.What is the PI in ADP?

ATP stands for adenosine triphosphate whereas

**ADP**stands for adenosine diphosphate.**Pi**is used to symbolized inorganic phosphate, that is, the phosphate released when ATP is hydrolyzed to**ADP**.What does PI stand for in the medical field?

Medical Definition of PI. PI: In medicine, not a private investigator but a

**principal investigator**, the person who directs a research project or program.