Exams › JEE Advanced › Chemistry

Among the isoelectronic series N3-, O2-, F-, Na+, Mg2+, the largest difference in ionic size is observed between which pair?

1. N3-, Mg2+
2. N3-, O2-
3. Mg2+, Na+
4. F-, Na+

Correct answer: N3-, Mg2+

Solution

All five species have 10 electrons. As nuclear charge increases from N(7) to Mg(12), the effective nuclear charge increases, pulling electrons closer. So N3- is the largest and Mg2+ the smallest — maximum size difference between the two extremes.

Related JEE Advanced Chemistry questions

• When the kinetic energy of an electron is quadrupled, how does the wavelength of its associated de-Broglie wave change?
• An electron labeled e₁ is in the fifth energy level, while another electron labeled e₂ is in the fourth energy level. The orbital radius of e₁ is five times that of e₂. What is the ratio of the speed of e₁ (v₁) to the speed of e₂ (v₂)?
• If the minimum wavelength of the spectral line in the Lyman series for a hydrogen atom is X, what is the maximum wavelength of the spectral line in the Balmer series for a Li²⁺ ion?
• For a sub-energy level with an azimuthal quantum number of 4, what are the highest and lowest possible spin multiplicities?
• The wave number is given by the formula ν = 1/λ = kZ² [1/n₁² - 1/n₂²]. For the Lyman series, the shortest wavelength (λₘₐₓ) occurs when n₁ = 1, n₂ = ∞, and Z = 1 (for a hydrogen atom). This simplifies to 1/λ = kZ² [1/1² - 1/∞²] ⇒ λ = 1/x. Which of the following statements is correct?
• In Bohr's theory, the electron with the greatest kinetic energy is found in:

⚔️ Practice JEE Advanced Chemistry free + battle 1v1 →