ALK or Alk may refer to:
In organic chemistry, an alkane, or paraffin (a historical name that also has other meanings), is an acyclic saturated hydrocarbon.
The alkaline earth metals are six chemical elements in column (group) 2 of the Periodic table. They are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).
The alkali metals are a group (column) in the periodic table consisting of the chemical elements lithium (Li), sodium (Na), potassium (K), rubidium (Rb), caesium (Cs), and francium (Fr).
In organic chemistry, an alkene is an unsaturated hydrocarbon that contains at least one carbon–carbon double bond.
Alkaloids are a group of naturally occurring chemical compounds that mostly contain basic nitrogen atoms.
Alkaline phosphatase (ALP, ALKP, ALPase, Alk Phos) (EC 22.214.171.124) is a hydrolase enzyme responsible for removing phosphate groups from many types of molecules, including nucleotides, proteins, and alkaloids.
Alkaline diet (also known as the alkaline ash diet, alkaline acid diet, acid ash diet, and the acid alkaline diet) describes a group of loosely related diets based on the belief that certain foods can affect the acidity and pH of bodily fluids, including the urine or blood, and can therefore be used to treat or prevent diseases.
Alkaline Trio is an American punk rock band from McHenry, Illinois. The band consists of guitarist and vocalist Matt Skiba, bassist and vocalist Dan Andriano, and drummer Derek Grant.
Alkalinity is the name given to the quantitative capacity of an aqueous solution to neutralize an acid.