Sodium (Na+) ion is mono-atomic since it consists of only one single charged atom.
What is a monoatomic ion?
A monatomic ion is an ion consisting of exactly one atom. The charge on the ion is the difference between the number of protons and electrons. If there are more protons, the charge is positive. If there is an excess of electrons, the charge is negative.
- KCl dissociates in water into K+ and Cl– ions. Both of these ions are monatomic ions. Ionization of an oxygen atom may result in O2-, which is a monatomic ion. Hydrogen usually forms the monatomic ion H+ it sometimes acts as an anion and forms H–.
- The monatomic ions that compose the salt are sodium (Na+) and chlorine (Cl–).