E

Electronic Transition

ΔE = hν = E₂ − E₁; selection rules: Δl = ±1
Quick Reference
Formula / NotationΔE = hν = E₂ − E₁; selection rules: Δl = ±1
Also Known AsElectron transition; atomic transition; spectroscopic transition; absorption/emission transition; UV-Vis transition

What is Electronic Transition?

An electronic transition is the movement of an electron from one energy level (orbital) to another, occurring through absorption or emission of a photon. The energy of the photon equals the difference in energy between the two levels (ΔE = hν). Electronic transitions in the UV-visible region give rise to the colour of compounds and are the basis of UV-Vis spectroscopy.

Formula & Notation

ΔE = hν = E₂ − E₁; selection rules: Δl = ±1

Other Names / Synonyms: Electron transition; atomic transition; spectroscopic transition; absorption/emission transition; UV-Vis transition

Properties & Characteristics

ΔE = hν = hc/λ; absorption: lower → higher energy state; emission: higher → lower energy state; UV transitions (~200–400 nm): electronic; visible (~400–700 nm): coloured compounds; fluorescence: S₁ → S₀ after vibrational relaxation; selection rules: spin-allowed (ΔS = 0), Laporte rule

Uses & Applications

UV-Vis spectroscopy for compound identification and quantification; flame tests (electronic transitions in metal ions); lasers; fluorescence microscopy; photochemistry; solar cell chromophores; dye chemistry

Safety Information

No hazard from the concept. UV radiation used in spectroscopy is harmful to eyes; use shielded instruments. Some photochemical processes can generate reactive intermediates.

Always consult the SDS/MSDS before handling any chemical. This information is for educational purposes only.

Key Facts

Term Electronic Transition
Formula ΔE = hν = E₂ − E₁; selection rules: Δl = ±1
Synonyms Electron transition; atomic transition; spectroscopic transition; absorption/emission transition; UV-Vis transition

Frequently Asked Questions

An electronic transition is the movement of an electron from one energy level (orbital) to another, occurring through absorption or emission of a photon. The energy of the photon equals the difference in energy between the two levels (ΔE = hν). Electronic transitions in the UV-visible region give rise to the colour of compounds and are the basis of UV-Vis spectroscopy.

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