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  2. Photochemical smog - Wikipedia

    en.wikipedia.org/wiki/Smog

    The chemical reactions that form smog following a volcanic eruption are different than the reactions that form photochemical smog. The term smog encompasses the effect when a large number of gas-phase molecules and particulate matter are emitted to the atmosphere, creating a visible haze. The event causing a large number of emissions can vary ...

  3. Peroxyacyl nitrates - Wikipedia

    en.wikipedia.org/wiki/Peroxyacyl_nitrates

    In organic chemistry, peroxyacyl nitrates (also known as Acyl peroxy nitrates, APN or PANs) are powerful respiratory and eye irritants present in photochemical smog. They are nitrates produced in the thermal equilibrium between organic peroxy radicals by the gas -phase oxidation of a variety of volatile organic compounds (VOCs), or by aldehydes ...

  4. Ground-level ozone - Wikipedia

    en.wikipedia.org/wiki/Ground-level_ozone

    Ground-level ozone is both naturally occurring and anthropogenically formed. It is the primary constituent of urban smog, forming naturally as a secondary pollutant through photochemical reactions involving nitrogen oxides and volatile organic compounds in the presence of bright sunshine with high temperatures. [35]

  5. Peroxyacetyl nitrate - Wikipedia

    en.wikipedia.org/wiki/Peroxyacetyl_nitrate

    It is a secondary pollutant present in photochemical smog. [1] It is thermally unstable and decomposes into peroxyethanoyl radicals and nitrogen dioxide gas. [2] It is a lachrymatory substance, meaning that it irritates the lungs and eyes. [3] Peroxyacetyl nitrate, or PAN, is an oxidant that is more stable than ozone. Hence, it is more capable ...

  6. NOx - Wikipedia

    en.wikipedia.org/wiki/NOx

    The presence of photochemical smog increases during the summer when the incident solar radiation is higher. The emitted hydrocarbons from industrial activities and transportation react with NO x quickly and increase the concentration of ozone and peroxide compounds, especially peroxyacetyl nitrate (PAN).

  7. Air pollution - Wikipedia

    en.wikipedia.org/wiki/Air_pollution

    Photochemical smog: particles are formed from gaseous primary contaminants and chemicals. [95] Smog is a type of pollution that occurs in the atmosphere. Smog is caused by a huge volume of coal being burned in a certain region, resulting in a mixture of smoke and sulfur dioxide. [96]

  8. Photoinitiator - Wikipedia

    en.wikipedia.org/wiki/Photoinitiator

    Nitrogen dioxide, a large contributor to the production of smog. Nitrogen dioxide can also be photolytically cleaved by photons of wavelength less than 400 nm [2] producing atomic oxygen and nitric oxide. NO 2 → NO + O. Atomic oxygen is a highly reactive species, and can abstract a H atom from anything, including water. O + H 2 O → 2 ·OH

  9. Photochemistry - Wikipedia

    en.wikipedia.org/wiki/Photochemistry

    Photochemical immersion well reactor (50 mL) with a mercury-vapor lamp.. Photochemistry is the branch of chemistry concerned with the chemical effects of light. Generally, this term is used to describe a chemical reaction caused by absorption of ultraviolet (wavelength from 100 to 400 nm), visible (400–750 nm), or infrared radiation (750–2500 nm).