The atomic number of fluorine is 9. How many electrons does an ion of fluorine have if it is represented by the symbol shown below?
A 8 electrons
B 9 electrons
C 10 electrons
D 20 electrons
The correct answer and explanation is :
The correct answer is C: 10 electrons.
Explanation:
Fluorine (F) has an atomic number of 9, which means that a neutral fluorine atom has 9 protons and 9 electrons. In its neutral state, the number of electrons equals the number of protons to balance out the charge.
However, the symbol for fluorine ion is often written as ( F^- ), which indicates that the fluorine atom has gained one electron, making it a negatively charged ion. The negative sign indicates an excess of electrons relative to protons. In this case, the fluorine ion has 1 more electron than the neutral atom, so it would have 10 electrons (9 electrons from the neutral atom + 1 additional electron).
Here’s a breakdown of the situation:
- Neutral Fluorine Atom:
- Atomic number = 9
- Electrons in a neutral atom = 9
- Since it is neutral, the number of electrons equals the number of protons.
- Fluorine Ion (( F^- )):
- This represents a negatively charged fluorine ion.
- Fluorine gains 1 electron, making it negatively charged.
- Thus, the fluorine ion will have 9 + 1 = 10 electrons.
To summarize, when fluorine gains an electron, it becomes an anion (( F^- )) with a total of 10 electrons. Therefore, the correct answer is C: 10 electrons.