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NEET 2026 · Nucleus: Composition, Size & Nuclear Force

Nucleus: Composition, Size & Nuclear Force question from NEET 2026

Q6NEET 2026Medium

Nucleus: Composition, Size & Nuclear Force

An unknown nucleus has a nuclear density of 2.29×1017 kg/m32.29 \times 10^{17}\text{ kg/m}^{3} and mass of 19.926×10−27 kg19.926 \times 10^{-27}\text{ kg}. Its mass number AA is approximately:

(Take R0=1.2×10−15 m,4π=12.56R_0 = 1.2 \times 10^{-15}\text{ m}, 4\pi = 12.56)

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Answer: (a)

  1. Volume of nucleus V=Mρ=19.926×10−272.29×1017=8.70×10−44 m3V = \dfrac{M}{\rho} = \dfrac{19.926 \times 10^{-27}}{2.29 \times 10^{17}} = 8.70 \times 10^{-44}\ \text{m}^3
  2. Also V=43πR03A=12.563(1.2×10−15)3A=7.23×10−45AV = \dfrac{4}{3}\pi R_0^3 A = \dfrac{12.56}{3}(1.2\times10^{-15})^3 A = 7.23 \times 10^{-45}A
  3. A=8.70×10−447.23×10−45≈12A = \dfrac{8.70 \times 10^{-44}}{7.23 \times 10^{-45}} \approx 12
  4. So the answer is (a) 12.
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