What is the english name for the element 'kalium'? 

Potassium 

The correct answer is option 2. Potassium.

The element commonly known as "kalium" is actually potassium. "Kalium" is the Latin name for potassium, and it was historically used in scientific literature. However, in English, the element is universally referred to as potassium.

Potassium is a chemical element with the symbol K and atomic number 19. It is a soft, silvery-white, highly reactive metal that belongs to the alkali metal group of the periodic table. Potassium is essential for various biological processes, including nerve function, muscle contraction, and maintaining fluid balance in the body.

Potassium compounds are widely used in agriculture, industry, and medicine. For example, potassium chloride is used as a fertilizer, potassium hydroxide is used in the production of soaps and detergents, and potassium iodide is used in medicine and photography.

In summary, "kalium" is the Latin name for the element with the chemical symbol K and atomic number 19, which is commonly known as potassium in English.