Which of the following elements is most likely to form a negative ion (anion)?

Correct option is C

The correct answer is (c) Chlorine (Cl)

Explanation:

• Chlorine is a halogen (Group 17), which has 7 valence electrons and needs one more electron to complete its outer shell. Therefore, it gains one electron to form a negative ion (anion), Cl⁻.

Information Booster:

Anions and Cations:

• Anions are formed when atoms gain electrons, while cations are formed when atoms lose electrons.
• Nonmetals like chlorine tend to gain electrons to form anions, while metals like sodium and calcium tend to lose electrons to form cations.

Chlorine (Cl): As a halogen, chlorine is highly reactive and readily forms the chloride ion (Cl⁻) when it gains an electron.

Uses of Chlorine:

• Water purification: Chlorine is widely used to disinfect drinking water and swimming pools.
• Bleaching agent: Used in the production of paper, textiles, and as a household cleaner.
• Production of chemicals: Key ingredient in the manufacture of PVC, solvents, pesticides, and various other chemicals.
• Disinfectant: Commonly used in cleaning products, especially for sanitizing surfaces and killing bacteria.

Additional Knowledge:

• Calcium is a Group 2 element and has a tendency to lose two electrons to form a positive ion (cation), Ca²⁺, rather than gaining electrons to form a negative ion.
• Aluminium is a Group 13 element and typically loses three electrons to form a positive ion (cation), Al³⁺. It does not tend to form negative ions.
• Sodium is a Group 1 element that typically loses one electron to form a positive ion (cation), Na⁺.