In chemistry, pH is a numeric scale used to specify the acidity or basicity(alkalinity) of an aqueous solution. It is roughly the negative of the logarithm to base 10 of the concentration, measured in units of moles  per liter, of hydrogen ions or H+. More precisely it is the negative of the logarithm to base 10 of the activity of the  hydrogen ion. Solutions with a pH less than 7 are acidic and solutions with a pH greater than 7 are basic. Pure water is neutral, being neither an acid nor a base. Contrary to popular belief, the pH value can be less than 0 or greater than 14 for very strong acids and bases respectively.

.ph is the Internet country code top-level domain (ccTLD) for the Philippines.

pH is a measure of acidity or alkalinity.

In organic chemistry, the phenyl group or phenyl ring is a cyclic group of atoms with the formula C₆H₅. Phenyl groups are closely related to benzene and can be viewed as a benzene ring, minus a hydrogen, serving as a functional group. Phenyl groups have six carbon atoms bonded together in a hexagonal planar ring, five of which are bonded to individual hydrogen atoms, with the remaining carbon bonded to a substituent. Phenyl groups are commonplace in organic chemistry. Although often depicted with alternating double and single bonds, phenyl groups are chemically aromatic and show nearly equal bond lengths between carbon atoms in the ring.