↩ 🔵 🔵 🔵 ❪✺❫ Spectroscopic Concepts ○ ❪✺₁❫ Electromagnetic Classes ○ ❪✺₁ᵢ❫ Color Classes ○ Gamma Ray ○꠹ Spectral Line ○꠹ Spectrum ○꠹ X-Ray ○꠹