Answer:
Cl⁻
Step-by-step explanation:
The chlorine ion Cl⁻ is the most similar to Argon from the given choices.
Argon is an element with 18 electrons.
It is a noble gas and so does not readily combine with other atoms.
Now,
For an atom to be similar to argon, it must have the same number of electrons which is 18.
- Cl⁻ is a chloride ion
- It has gained one electron to its initial 17 electrons thus making the number 18
- The net charge is a negative ion.