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#mass number

8 public questions tagged with this topic.

PHYSICS

What is the approximate mass number of a nucleus with radius 4.8 × 10⁻¹⁵ m ? (Given R_0 = 1.2 × 10⁻¹⁵ m )

Given: What is the approximate mass number of a nucleus with radius 4.8 × 10⁻¹⁵ m ? (Given R_0 = 1.2 × 10⁻¹⁵ m ) These values define the system as per NCERT data. Formula: R = R_0 A^{1/3. This is the standard NCERT relation for this phenomenon. Substitution & Calculation: 4.8 × 10⁻¹⁵= 1.2 × 10⁻¹⁵ × A^{1/3 . A^{1/3 = 4.8/1.2 = 4 . A = 4³ = 64 . Result: The computed value matches the expected outcome and confirms the correct choice. Units and powers like J kg⁻¹ K⁻¹, m/s², 10⁻⁵ are properly used as per NCERT.

Ref: NCERT Physics Textbook for Class XI and XII, Chapter: Dual Nature, Atoms, Nuclei and Electronic Devices, Topic: Atomic structure, nuclear binding and semiconductor physics.

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Radioisopes and Field Biology methods

Which decay results in decrease in atomic number by 2 and mass number by 4?

Alpha decay ejects a helium-4 nucleus containing two protons and two neutrons. Parent nucleus therefore loses atomic number by two, shifting element position in periodic table, and mass number by four, reflecting loss of four nucleons. This contrasts with beta decay, where mass number remains unchanged and atomic number changes by one, and gamma decay where neither changes. Alpha emission is common in heavy unstable nuclei seeking stability and produces daughter nuclei with significantly lower mass, readily identifiable by alpha spectroscopy and mass balance.

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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