3 public questions tagged with this topic.
Noble gases have positive electron gain enthalpies due to their stable configurations. Ne (group 18) requires energy to add an electron, unlike O, S, or Cl.
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Electron Gain Enthalpy and Electronegativity and Valency
Total electrons = 18, corresponding to Ar (period 3, group 18). Others: Cl (17 electrons), K (19 electrons), S (16 electrons).
Ref: NCERT Class 11 Chemistry > Chapter 3: Classification of Elements and Periodicity in Properties > Topic: Anomalous Properties and Second Period and Chemical Reactivity
Number of protons accurately defines or describes the concept asked in this question. Within Atoms and Molecules, precise definitions and terminology are essential for clear scientific communication. The other options (Number of neutrons, Number of electrons, and Both b and c) either describe related but distinct concepts, use incorrect terminology, or confuse similar-sounding terms that have different scientific meanings. A thorough understanding of exact definitions helps distinguish between closely related biological concepts and is crucial for competitive examinations.
Ref: Campbell Biology, Urry et al., 12th Ed.
