What can be said about the Lewis dot structure for an ion of fluorine depicted below: F It is incorrect, as the fluorine atom can only accommodate 7 total electrons and cannot form an ion. It is incorrect because the fluorine atom cannot accommodate a negative charge. It is incorrect, as the fluorine ion cannot achieve an octet of electrons. It is correct as the neutral fluorine atom has 8 valence electrons. It is correct as the negative charge represents the additional valence electron added to the neutral fluorine atom.
The Correct Answer and Explanation is:
Correct Answer:
It is correct as the negative charge represents the additional valence electron added to the neutral fluorine atom.
Explanation:
The Lewis dot structure is a useful way to represent the valence electrons of an atom or ion, which are the electrons involved in chemical bonding. For the element fluorine (symbol F), the neutral atom has seven valence electrons. This is because fluorine is in Group 17 (the halogens) of the periodic table, and elements in this group typically have seven electrons in their outermost shell.
Fluorine has a very high electronegativity and a strong tendency to gain one electron to complete its octet. When a fluorine atom gains one additional electron, it becomes a fluoride ion, denoted as F⁻. This ion has eight valence electrons—seven from the original fluorine atom and one from the gained electron. These eight electrons satisfy the octet rule, which states that atoms tend to form bonds or ions in ways that give them eight electrons in their outer shell, mimicking the stable electron configuration of noble gases.
In the Lewis dot structure for the fluoride ion (F⁻), the symbol “F” is surrounded by eight dots, representing the eight valence electrons. A negative sign is placed near the symbol or outside a bracketed structure to indicate the extra electron and the negative charge of the ion. The correct notation often appears as [F⁻] with eight surrounding dots.
It is incorrect to say that fluorine cannot form an ion or that it cannot carry a negative charge. Fluoride ions are very common and are found in compounds such as sodium fluoride (NaF) and in many oral health products due to their ability to help prevent tooth decay. Therefore, the depiction of the fluoride ion as a fluorine atom with eight valence electrons and a negative charge is correct and consistent with chemical principles.
