Question

Is potassium a metal or nonmetal?

Answer 1

Potassium is the third member of the alkali group of the periodic table. It is soft and has a silvery-white appearance. Potassium is silvery when first cut but it oxidizes rapidly in air and tarnishes within minutes, so it is generally stored under oil or grease. It has an atomic number of $19$ and an atomic mass of $39.098g/mol$.

Complete answer:
The first group of periodic table is called the alkali metal group. Potassium is present at the third position in this group after lithium and sodium. It is succeeded by rubidium, caesium. It is light enough to float into water with which it reacts instantly to release hydrogen, which burns with a lilac flame. Most potassium occurs in the Earth's crust as minerals, such as feldspars and clays. Minerals mined for their potassium are pinkish and sylvite, carnallite and alunite.
Hence, potassium is a metal. In fact, it is the most reactive metal in the periodic table.
The ionization enthalpy of potassium is minimum. It is the most electropositive and most reactive metal. It reacts with air as well as water vigorously. The reactions are highly exothermic and hence, the hydrogen gas evolved as a by-product that catches fire.
Potassium plays an important role in the physical fluid system of humans and it assists nerve functions. Potassium, as the ion ${K^ + }$, concentrates inside cells, and $95\%$ of the body's potassium is so located. Potassium can be found in vegetables, fruit, potatoes, meat, bread, milk and nuts.

Note:
Low potassium levels in soil are apparent in a variety of symptoms: restricted growth, reduced flowering, lower yields and lower quality produce for crops and plants.
In human beings, when the kidneys are somehow malfunctioning an accumulation of potassium will consist. This can lead to disturbing heartbeats. Higher exposures to it may cause a build-up of fluid in the lungs, this can cause death. Skin and eye contact can cause severe burns leading to permanent damage.