All questions of Chemical Bonding - Ionic Compounds and Covalent Compounds for Class 10 Exam

Noble Gases Overview
Noble gases are a unique group of elements found in Group 18 of the periodic table. They include helium, neon, argon, krypton, xenon, and radon. Their distinctive properties make them fascinating in the study of chemistry.
Correct Answer: Option B
The statement "They have a complete outermost shell" is true for noble gases. Here's why:
Complete Outermost Shell
- Noble gases have an electron configuration that results in a full outer shell, typically with eight electrons (except for helium, which has two).
- This full outer shell configuration makes them highly stable and less likely to react with other elements.
High Ionization Potential
- While noble gases do have high ionization potentials (option A), this statement alone does not define their chemical behavior as accurately as option B does.
Reactivity
- Noble gases are known for their lack of reactivity (option C). They do not readily participate in chemical reactions owing to their stable electronic configuration.
Electron Loss
- The statement about noble gases easily losing electrons (option D) is also incorrect. Due to their full outer shell, they are unlikely to lose electrons, making them inert.
Conclusion
In summary, the defining characteristic of noble gases is their complete outermost shell, which leads to their stability and lack of reactivity, confirming that option B is the correct answer.

Understanding Electron Affinity
Electron affinity refers to the amount of energy released when an electron is added to a neutral atom in the gas phase. This property is significant in understanding how non-metallic atoms interact during chemical bonding.
Importance of Electron Affinity
- Facilitates Anion Formation: Higher values of electron affinity indicate that the atom has a strong tendency to gain electrons, making it easier for the atom to form anions. Non-metals typically have high electron affinities because they are more electronegative and tend to attract electrons to achieve a stable electron configuration.
- Bond Formation: In chemical reactions, non-metals often gain electrons to form stable anions. This process is crucial for ionic and covalent bond formation, particularly in compounds where non-metals interact with metals or other non-metals.
Why Other Options are Incorrect
- Only Applies to Metals (a): This is false because electron affinity is a property that applies primarily to non-metals, which readily gain electrons.
- Irrelevant in Bond Formation (b): Electron affinity is very relevant; it directly influences how atoms bond and the stability of the resulting compounds.
- Always Low (c): This statement is incorrect as non-metals generally possess high electron affinities, reflecting their ability to easily gain electrons.
Conclusion
In summary, option 'D' is correct because higher electron affinity values indeed facilitate anion formation, highlighting the fundamental role this property plays in the chemistry of non-metals. Understanding electron affinity helps predict the behavior of non-metallic atoms in various chemical reactions.

Understanding Ionic Bonding and Electron Transfer
Ionic bonding is a fundamental concept in chemistry that involves the transfer of electrons between atoms, primarily between metals and non-metals.
Electron Transfer in Ionic Bonding
- In ionic bonding, electrons are transferred from metals to non-metals.
- Metals, which are typically located on the left side of the periodic table, have a tendency to lose electrons due to their low electronegativity and low ionization energy.
- Non-metals, found on the right side of the periodic table, tend to gain electrons because they have higher electronegativity and a greater tendency to fill their outer electron shells.
Why Option B is Correct
- Metals lose electrons: When a metal atom (e.g., sodium) loses an electron, it becomes a positively charged ion (cation).
- Non-metals gain electrons: When a non-metal atom (e.g., chlorine) gains an electron, it becomes a negatively charged ion (anion).
- The resulting electrostatic attraction between the positively charged cation and the negatively charged anion forms a stable ionic bond.
Other Options Explained
- Option A (Electrons remain with their respective atoms): This is incorrect as ionic bonds involve the transfer of electrons.
- Option C (Electrons are transferred from non-metals to metals): This is also incorrect; the transfer is in the opposite direction.
- Option D (Electrons are shared equally): This describes covalent bonding, not ionic bonding, where electrons are shared rather than transferred.
In summary, option B accurately describes the process of electron transfer in ionic bonding, highlighting the crucial role of metals losing electrons and non-metals gaining them to achieve stability.