Fluorine has an atomic number of 9. Which of the following is true of fluorine?
A. It will lose an electron to become a cation.
B. It will gain an electron to become an anion.
C. It will form two covalent bonds to fill its outer shell.
D. It will form three covalent bonds to fill its outer shell.
The correct answer is B. It will gain an electron to become an anion.
Fluorine has 9 protons in its nucleus, which means it also has 9 electrons in its neutral state. To achieve a full outer electron shell, fluorine only needs one additional electron. Therefore, it is more likely to gain one electron to become an anion with a charge of -1 rather than losing an electron to become a cation. Covalent bonds are formed by the sharing of electrons, not gaining or losing them, so options C and D are incorrect.