Answer:
Potassium is a chemical element with the symbol K and the atomic number 19. (from Neo-Latin kalium). Potassium is a delicate silvery-white metal that can be easily sliced with a knife. In mere seconds of exposure, potassium metal interacts with ambient oxygen to generate flaky white potassium peroxide.
Potassium is atomic number 19.
Mass number = Protons + Neutrons
Mass number = 19+18
Mass Number of Potassium = 37 amu.