Photochemistry — Definition, Formula, Properties & Uses | AllChemicals | AllChemicals

Q: What is the formula for Photochemistry?

The formula or notation for Photochemistry is: A + hν → A* → products; Φ = products/photons

Formula / Notation	A + hν → A* → products; Φ = products/photons
Also Known As	Photochemistry, photochemical reaction, photochemical process, light-induced chemistry

What is Photochemistry?

The branch of chemistry concerned with chemical reactions and physical processes initiated by the absorption of light (photons). Photochemical reactions include photosynthesis, photography, ozone formation, and vision. The energy of absorbed photons drives the reaction.

Formula & Notation

A + hν → A* → products; Φ = products/photons

Other Names / Synonyms: Photochemistry, photochemical reaction, photochemical process, light-induced chemistry

Properties & Characteristics

Photochemistry is the branch of chemistry studying chemical reactions initiated by the absorption of light (photons). When a molecule absorbs a photon, it reaches an electronically excited state, which may undergo: fluorescence (emission, return to ground state), photodissociation (bond cleavage), photoisomerisation (e.g., cis-trans isomerisation), energy transfer, or electron transfer (photoredox). The quantum yield (Φ) measures the efficiency of a photochemical process: Φ = mol of product / mol of photons absorbed.

Uses & Applications

Photochemistry drives: photosynthesis (solar energy conversion), vision (11-cis-retinal photoisomerisation to all-trans), photography (AgBr photodecomposition), sunscreen design (absorb UV to protect skin), photodynamic therapy (PDT for cancer), organic solar cells (photoexcited charge separation), and ozone chemistry (stratospheric photolysis of O₃ and CFCs).

Safety Information

UV photons used in photochemical reactions can cause skin burns and eye damage (photokeratitis). High-power UV lamps, excimer lasers, and broad-spectrum UV sources require appropriate enclosures and UV-protective eyewear. Some photochemical intermediates (singlet oxygen, reactive radicals) are toxic to biological tissue.

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

Key Facts

Term Photochemistry

Formula A + hν → A* → products; Φ = products/photons

Index All "P" terms

Synonyms Photochemistry, photochemical reaction, photochemical process, light-induced chemistry

Frequently Asked Questions

What is Photochemistry?

The branch of chemistry concerned with chemical reactions and physical processes initiated by the absorption of light (photons). Photochemical reactions include photosynthesis, photography, ozone formation, and vision. The energy of absorbed photons drives the reaction.

What is Photochemistry used for?

Is Photochemistry hazardous?

What is the formula for Photochemistry?

More "P" Terms

P-type Semiconductor Pairing Pairing Energy Palladium Pd Parachor [P] = M(γ)^(1/4) / (ρ_L - ρ_V) Paramagnetic χ_m > 0; unpaired electrons; μ = √(n(n+2)) BM (n = unpaired electrons) Paramagnetism Partial Ionic Character % ionic = (1 - e^(-Δχ²/4)) × 100% Partial Pressure Partial Pressure p_i = x_i × P_total; P_total = Σp_i Particulate Matter Parts Per Million ppm = mg/L (water) or mg/kg; = (mass solute/mass solution) × 10⁶

View all "P" terms →