Which best describes the potassium ion that forms?
The Correct Answer and Explanation is:
The potassium ion (K⁺) that forms is a positively charged ion, or cation, formed when a potassium atom loses one electron.
Correct Answer: K⁺ (Potassium ion)
Explanation:
Potassium (K) is an element in Group 1 of the periodic table, known as an alkali metal. Alkali metals have a single electron in their outermost electron shell. This electron is loosely bound and can be easily lost during chemical reactions, leading to the formation of positively charged ions. When potassium undergoes ionization, it loses this single valence electron to achieve a more stable electron configuration, similar to the noble gas argon, which has a complete outer shell of electrons.
The process of ionization for potassium can be described as follows:
- Electron loss: Potassium (K) has the atomic number 19, meaning it has 19 electrons in total. The electron configuration of potassium is 2, 8, 8, 1, with one electron in its outermost shell. This single electron in the outer shell is easily lost because the outer shell is far from the nucleus and is not strongly held by the nuclear charge. The removal of this electron requires energy, known as ionization energy.
- Formation of K⁺: Once the electron is lost, the potassium atom becomes a positively charged ion, K⁺. The loss of a negative charge results in a net positive charge, as the number of protons (positively charged particles in the nucleus) exceeds the number of electrons.
- Stability: The resulting K⁺ ion has a stable electron configuration similar to argon (2, 8, 8), which is more stable than the neutral potassium atom’s original configuration. This stability is what drives the ionization process. The K⁺ ion can now participate in ionic bonds, such as when it bonds with anions like chloride (Cl⁻) to form potassium chloride (KCl), a common ionic compound.
In summary, a potassium ion (K⁺) is formed when potassium loses its single outer electron, creating a stable cation with a +1 charge. This process is essential in many biological and chemical processes, including nerve transmission and muscle function.