Final answer:
The symbols for the ions of the given elements are F-, Mg2+, Rb+, and Br-.
Step-by-step explanation:
The symbol for the ion of each of the following elements is as follows:
- Fluorine: F-
- Magnesium: Mg2+
- Rubidium: Rb+
- Bromine: Br-
These symbols represent the charge of the ion. For example, F- indicates that fluorine has gained one electron and has a charge of -1.