Question

What is the symbol for the ion with \[19\] protons and \[18\]electrons \[?\]

Answer 1

Hint: Before finding the symbol for the ion when the number of protons and electrons are given. First, understand the basic definitions and formulas. After finding the ion, check that the given ion is positively charged or negatively charged based on the number of electrons present in the ion.

Complete step-by-step answer:
An ion is a small particle having an electrical charge. Simply an ion is a charged atom or molecule, Ions are either single charged atoms known as simple ions or small charged molecules known as polyatomic ions. Examples of simple ions are \[N{a^ + }\],\[C{l^ - }\], etc. Examples of polyatomic ions are \[SO_4^{2 - }\],\[CO_3^{2 - }\] and \[O{H^ - }\].

An atom consists of a positively charged nucleus, surrounded by one or more negatively charged particles called electrons. The positive charges equal to the negative charges. The nucleus of an atom contains protons and neutrons.

Since given that there are \[19\] protons, i.e., \[Z = 19\]. The element is necessarily potassium. Since also given that there are \[18\] electrons. Hence it has one less electron than the defining nuclear charge, so potassium loses one electron when it is reacting with other ions.

Hence, we got positive potassium ion i.e., \[{K^ + }\].

Note: Note that the positively charged ions are called cations and negatively charged ions are called anions. A cation is formed by the loss of one or more electrons by an atom and an anion is formed by the gain of one or more electrons by an atom.