Size of the nucleus: R = R₀A^(1/3)नाभिक का आकार: R = R₀A^(1/3)Size of the nucleus: R = R₀A^(1/3)

NCERT Section 13.3 · Class 12 Physics · Chapter 13 · interactive diagram

Parts and what they mean

• R = R₀A^(1/3) (R = R₀A^(1/3)) — Radius grows only as the cube root of A: 8 times the nucleons → only 2 times the radius. R₀ = 1.2 fm = 1.2 × 10⁻¹⁵ m.
• ⁴He: R ≈ 1.9 fm (⁴He: R ≈ 1.9 fm) — R = 1.2 × 4^(1/3) = 1.9 fm.
• ¹⁶O: R ≈ 3.0 fm (¹⁶O: R ≈ 3.0 fm) — R = 1.2 × 16^(1/3) = 3.0 fm.
• ⁵⁶Fe: R ≈ 4.6 fm (⁵⁶Fe: R ≈ 4.6 fm) — R = 1.2 × 56^(1/3) = 4.6 fm (used in NCERT Example 13.1).
• ²³⁸U: R ≈ 7.4 fm (²³⁸U: R ≈ 7.4 fm) — 238 nucleons but the radius is only about 4 times that of ⁴He (238/4 ≈ 60, and 60^(1/3) ≈ 3.9).

Original diagram drawn by Simple Learning Hub, based on NCERT Section 13.3. Report a mistake