the fluoride anion always carries a charge of 1- true or false
I say true
True. The flouride anion is an ion of fluorine. Fluorine has only one oxidation state, of -1. WHY: Fluorine is the most electronegative element on the periodic table meaning that having an extra electron is very energetically favorable. (It "wants" one electron) In the F- ionic state it becomes iso-electronic with Neon, a noble gas. The noble gas characteristic, like non-re-activity and stability stem from the fact that it has all of its orbital completely filled. Thus it makes sense energetically that the F- ion formation would be favorable.
You are correct, the statement "the fluoride anion always carries a charge of 1-" is true.
To determine the charge on an ion, we need to consider its atomic number and the number of electrons it either gains or loses to achieve a stable electron configuration.
Fluoride (F) is an element with atomic number 9. It has 9 protons in its nucleus and 9 electrons in its neutral state. In order to achieve a stable electron configuration, fluorine tends to gain one electron.
When fluorine gains one electron, it now has 10 electrons and 9 protons. Since the number of protons (positive charge) is less than the number of electrons (negative charge), the fluoride ion carries a charge of 1-. This negative charge indicates that it has gained one electron.