#crystallography

Production of EM Waves and Hertz Experiment

Why are X-rays used in crystallography to study atomic structures?

**Hertz experiment** used induction coil connected to two rods with gap, spark produced oscillating charge, emitted EM wave, received by loop with gap sparking when E induced, measured wavelength by standing wave, demonstrated EM wave properties, validating Maxwell. X-rays have wavelengths comparable to atomic spacings, allowing them to diffract off crystal lattices and produce interference patterns that reveal atomic arrangements. Using c = fλ, E₀/B₀ = c, I_d = ε₀ dΦ_E/dt, and spectrum classification λ = c/f, evaluation yields Comparable wavelengths, illustrating EM wave transverse nature and

Ref: NCERT > Physics Book > Electromagnetic Waves > Production of EM Waves and Hertz Experiment

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CHEMISTRY

Which of the following 3d series elements has a body-ntered cubic (bcc) lattice structure at normal temperatures?

Vanadium (V) has a bcc structure, contributing to its high melting point and strength. This follows from latest NCERT 2026-27 principle explaining the concept clearly for NEET students in simple steps as per rationalized syllabus.

Ref: NCERT Chemistry Textbook - Latest Edition for Academic Session 2026-27 (Rationalized Textbook for Class XI and XII)Topic: Mole concept, atomic structure, chemical formulas like H₂O, CO₂, CH₃CH₂NH₂ and periodic trends.

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X Ray, IR Spectroscopy

Which crystal property enables diffraction in XRD?

Diffraction arises from long-range three-dimensional order where atoms are positioned with periodic repetition defined by unit cell parameters a, b, c and angles. Constructive interference occurs only when scattering from thousands of identical cells aligns in phase according to Bragg's law. This periodic array amplifies weak atomic scattering into measurable spots. Properties like polarizability govern Raman scattering, optical density affects absorption, heat capacity relates to energy storage, but none produce coherent diffraction. Consequently, ability to form crystals with consistent unit

Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.

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X Ray, IR Spectroscopy

Which step reconstructs the electron density map in XRD?

Diffraction experiment records intensities yielding amplitudes of structure factors but loses phase information, known as phase problem. To recover real-space electron distribution, crystallographers apply Fourier transformation, specifically inverse Fourier synthesis of structure factors F(hkl) incorporating experimentally determined amplitudes and computationally estimated phases. Crystallization generates ordered lattice, radiation exposure creates diffraction pattern, drying is irrelevant to map generation. Phase determination via molecular replacement, anomalous dispersion or heavy-atom i

Ref: NCERT Biology Class XII Principles on Klenow fill-in labeling, Lehninger Chapter 9 DNA cloning techniques, and Molecular Cloning by Sambrook Chapter 10 documenting end-labeling of cohesive termini.

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