⚛️ Bohr Model (Atomic Structure)

Radius, velocity, energy, Rydberg formula, Lyman / Balmer / Paschen series

rₙ = 0.529 n² Å Eₙ = −13.6 Z²/n² eV 1/λ = R Z²(1/n₁²−1/n₂²)
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💡 Bohr model

In the Bohr model, the electron orbits the nucleus in quantized orbits. Radius rₙ = 0.529 n² Å (H); velocity vₙ = 2.19×10⁶/n m/s; energy Eₙ = −13.6 Z²/n² eV. Transitions: ΔE = 13.6 Z²(1/n₁² − 1/n₂²) eV. Rydberg: 1/λ = R Z²(1/n₁² − 1/n₂²). Angular momentum L = n ℏ. Series: Lyman (n₁=1), Balmer (n₁=2), Paschen (n₁=3).

Bohr model calculators

Radius, velocity, energy, transition, Rydberg, angular momentum

Principal quantum number (n)
n = 1,2,3...
Atomic number (Z)
H=1, He⁺=2
Radius of nth orbit
0.529 Å
Principal quantum number (n)
n = 1,2,3...
Atomic number (Z)
Z
Velocity of electron
2.19×10⁶ m/s
Principal quantum number (n)
n
Atomic number (Z)
Z
Energy of nth orbit
−13.6 eV
Initial orbit (n₂, higher)
n₂
Final orbit (n₁, lower)
n₁ (emission n₂→n₁)
Atomic number (Z)
Z
ΔE, wavelength, frequency
n₁ (lower, final)
Lyman=1, Balmer=2, Paschen=3
n₂ (higher, initial)
n₂ > n₁
Atomic number (Z)
Z
Wavenumber & wavelength
Principal quantum number (n)
n = 1,2,3...
Angular momentum (L = n ℏ)
1.05×10⁻³⁴ J·s

⚛️ Bohr model summary

Run a calculation to see result.
🧮Step-by-Step Solution▼ Show
Concept Formula Notes
Radius of nth orbit rₙ = 0.529 n² Å (H), rₙ ∝ n²/Z Hydrogen-like atoms
Velocity of electron vₙ = (2.19×10⁶ / n) m/s (H), vₙ ∝ Z/n vₙ ∝ 1/n for fixed Z
Angular momentum L = n ℏ = n h / (2π) n = 1,2,3,...
Energy of nth orbit Eₙ = −(13.6 Z² / n²) eV Hydrogen (Z=1): −13.6/n² eV
Energy difference (transition) ΔE = 13.6 Z² (1/n₁² − 1/n₂²) eV Emission when n₂ > n₁
Wavenumber (Rydberg) 1/λ = R Z² (1/n₁² − 1/n₂²) R ≈ 1.097×10⁷ m⁻¹
Frequency of photon ν = c/λ = ΔE/h
Series limits Lyman (n₁=1), Balmer (n₁=2), Paschen (n₁=3) UV, visible, IR

About the Bohr model

In the Bohr model, the electron moves in circular orbits with quantized angular momentum L = n ℏ. For hydrogen-like atoms (nucleus charge Ze): radius rₙ = 0.529 n²/Z Å, velocity vₙ ∝ Z/n, and energy Eₙ = −(13.6 Z²/n²) eV. Transitions between orbits give spectral lines: ΔE = 13.6 Z²(1/n₁² − 1/n₂²) eV and 1/λ = R Z²(1/n₁² − 1/n₂²) (Rydberg formula).

Spectral series

Lyman (n₁=1, UV), Balmer (n₁=2, visible), Paschen (n₁=3, IR), Brackett (n₁=4), Pfund (n₁=5).