Which of the following is a common property of non-metals?

Analysis of the Question

This question tests your understanding of the periodic trends and chemical behaviors of elements, specifically the fundamental differences between metals and non-metals.

Concept Explanation

To identify the correct property, let’s look at the nature of non-metals:

• Electronic Configuration: Non-metals typically have 4 to 7 electrons in their outermost shell (valence shell). To achieve a stable octet (like noble gases), they need to gain electrons.
• Electronegativity: Because they have high effective nuclear charges, they have a strong tendency to attract electrons toward themselves.
• Metals vs. Non-metals: • Metals generally lose electrons to form cations (positively charged ions). • Non-metals generally gain electrons to form anions (negatively charged ions). • Physical Properties: Metals are generally good conductors of heat and electricity and are mostly solids (except Mercury). Non-metals are poor conductors and exist in various states (solids, liquids, or gases).

Step-by-Step Evaluation of Options

• Option A: Incorrect. While some non-metals are solids (like Carbon or Sulfur), many are gases (like Oxygen or Nitrogen) or liquids (like Bromine) at room temperature.
• Option B: Correct. Because non-metals have high electronegativity and need to complete their valence shells, they readily gain electrons to form negative ions (anions).
• Option C: Incorrect. Non-metals are generally poor conductors of heat and electricity (insulators).
• Option D: Incorrect. Forming cations (positive ions) is a characteristic property of metals, which lose electrons easily.

Conclusion

Based on the chemical behavior of non-metals, they are characterized by their ability to gain electrons during chemical reactions to achieve stability.

Exam Tip: Remember the mnemonic "OIL RIG": Oxidation Is Loss (of electrons, typical of metals), Reduction Is Gain (of electrons, typical of non-metals). Since non-metals gain electrons, they are the ones that undergo reduction in chemical reactions!