Visual Overview: Atoms & Nuclei
Hydrogen Energy Level Diagram:
H Energy Levels and Spectral Regions n=1 -13.6 eV n=2 -3.4 eV n=3 -1.51 eV n=4 -0.85 eV n=5 -0.54 eV n=∞ 0 eV Lyman (UV) Balmer (Vis) Paschen (IR)Bohr Model Quick Reference:
| Quantity | Formula | n=1,Z=1 (Ground H) | n=2,Z=1 | n=3,Z=1 |
|---|---|---|---|---|
| Radius | 0.529/Z Å | 0.529 Å | 2.116 Å | 4.761 Å |
| Velocity | Z/n m/s | m/s | m/s | m/s |
| Energy | −13.6/ eV | −13.6 eV | −3.4 eV | −1.511 eV |
| KE | +13.6/ eV | +13.6 eV | +3.4 eV | +1.511 eV |
| PE | −27.2/ eV | −27.2 eV | −6.8 eV | −3.022 eV |
Nuclear Properties Table:
| Property | Formula | Value/Notes |
|---|---|---|
| Nuclear radius | R = 1.2 × A^(1/3) fm | ~1.2–8 fm depending on A |
| Nuclear density | ρ = Am_u/V | ≈ kg/ (constant) |
| Mass defect | = [Zm_p+(A-Z)m_n]−M | Always positive for stable nuclei |
| Binding energy | BE = × 931.5 MeV | Ranges from ~7 to ~8.75 MeV/nucleon |
| Most stable | Fe-56 | BE/A ≈ 8.75 MeV/nucleon |
| Half-life | t_{1}/_{2} = 0.693/λ | Property of each isotope |
| Mean life | τ = 1/λ = 1.443 t_{1}/_{2} | Always > t_{1}/_{2} |