Chemistry - PERIODIC TABLE Question with Solution | TestHub
An atom X belongs to the 3 rd period. The successive ionization energies ( to ) are . The first electron gain enthalpy is -3.4 eV . If the lattice energy of is -25 eV and the bond dissociation energy of is 2.5 eV , and of Cl is 3.6 eV , what can be concluded about the of X if the formation of is just barely feasible ( )?
Options:
Answer:
Solution:
Question Explanation: Analyzing ionization energy jumps to identify the nature of element X.
Concept: Successive Ionization Energies and Born-Haber Cycle
Solution:
1. Looking at IE: IE₁ = 100, IE₂ = 200, IE₃ = 3000. There is a massive jump at IE₃, meaning X has 2 valence electrons (Group 2, Magnesium).
2. For metals, we don't discuss EA₂. EA₂ is a property of non-metals forming anions.
3. The values provided for Cl and lattice energy are to test if you can distinguish between the energy required to form a cation (IE) vs. an anion (EA).
4. Choice (A) correctly identifies that EA₂ is conceptually inappropriate for an element whose IE profile indicates it is a metal.
Final Answer: EA₂ is not applicable here; the data describes a metal.