Final answer:
The ion symbols for an iodine atom that has gained one electron, a zinc atom that has lost two electrons, a gallium atom that has lost three electrons, and a sodium ion are I^-, Zn^2+, Ga^3+, and Na^+ respectively. The formation of these ions is due to the loss or gain of electrons by the atoms.
Step-by-step explanation:
These are the ion symbols for each of the ions as per the question: a) An iodine atom gains one electron to become a negatively charged ion, which is represented as I^-. b) A zinc atom loses two electrons to form a positively charged ion represented as Zn^2+. c) A gallium atom loses three electrons resulting in a positively charged ion, represented as Ga^3+. d) A sodium ion is always represented as Na^+.
When atoms lose or gain electrons, they form ions. Atoms that lose electrons become positively charged and are referred to as cations. On the other hand, atoms that gain electrons become negatively charged and are called anions.
You can use the periodic table to predict whether an atom will form an anion or a cation, and you can also predict the charge of the resulting ion. Atoms of many main-group metals lose enough electrons to leave them with the same number of electrons as an atom of the preceding noble gas. To illustrate, a neutral calcium atom, with 20 protons and 20 electrons, readily loses two electrons, resulting in a cation with 20 protons, 18 electrons, and a 2+ charge. It is symbolized as Ca²+.
Learn more about Ion Symbols