Understanding Chlorine
* Atomic Number: Chlorine has an atomic number of 17, meaning it has 17 protons and 17 electrons in its neutral state.
* Electron Configuration: The electron configuration of a neutral chlorine atom is 2, 8, 7. This means it has 7 electrons in its outermost shell.
Achieving Stability
* Octet Rule: Atoms tend to gain, lose, or share electrons to achieve a stable configuration of 8 electrons in their outermost shell (except for hydrogen and helium, which are stable with 2).
* Ionization: Chlorine is highly electronegative, meaning it has a strong tendency to gain electrons. To achieve a stable octet, it gains one electron.
The Correct Symbol
When chlorine gains an electron, it becomes a negatively charged ion called a chloride ion. The correct symbol is:
C. 35Cl⁻
* 35: This is the mass number of the chlorine atom (protons + neutrons).
* Cl: This is the chemical symbol for chlorine.
* ⁻: This indicates the negative charge due to gaining one electron.
Why the other options are incorrect:
* A. 35Cl1: This symbol suggests a +1 charge, which is incorrect for a chloride ion.
* B. 35Cl2: This symbol suggests a +2 charge, which is also incorrect.
* D. 35Cl: This symbol represents a neutral chlorine atom, not an ion.
