AgCL

Ja, det er i grunden meget mærkeligt idet en hvid farve er ensbetydende med refleksion med alle bølgelængder.

Men de er jo netop tilstede i sollys!!

Forstår det heller ikk rigtig.

Måske er AgCl reaktivt over for UV.
Bare et gæt

det må være noget med det. For hvis der ikke sker noget med AgCl kan det ikke hænge sammen.

AgCl må derimod være reaktivt overfor lys, evt. UV-lys. Hvor det spaltes eller oxideres eller noget. Det der dannede stof må så være lilla i sollys, mens AgCl i ren form må være hvidt

fra hvad jeg kan forstå er det ngt med at chloriden forsinder fra AgCl efter længere tids lys... det sølv der er tilbage vil være der som metal, der derfor er farvet...

det kan da ikke bare forsvinde??

Hvor har du det fra?

det er den reaktion man bruger når man tager billeder tror jeg...

http://www.bgsu.edu/departments/chem/faculty/endres/ch128/photo_lab/intro_silver.htm

"Johann Wilhelm Ritter (1776 - 1810) was famous as the discoverer of electroplating. In 1801 he was experimenting with a chemical called silver chloride (AgCl). This chemical is decomposed by light, liberating silver which makes the colourless substance turn black. This reaction is the basis of pre-digital photography. In chemistry at that time there was a rumour that blue light was more efficient at initiating chemical change than red light. Ritter tried to measure the speed at which silver chloride broke down with different colours. He proved that blue light was indeed more efficient that red light. He was amazed, however, that the most vigorous reactions took place in the region beyond the violet where nothing could be seen. This new radiation was originally called Chemical Rays but is now called Ultra Violet (beyond the violet). Ultra Violet differs from visible light only in its wavelength which is shorter."

fra : http://www.krysstal.com/spectrum.html

--- så ja, det med uv er korrekt!!

Flere detaljer:

"Silver salts are converted to silver in the chemistry of photographic exposure of the film.

Silver chloride (AgCl), silver bromide (AgBr) and silver iodide (AgI) are all sensitive to light ('photosensitive'), and all three are used in the production of various types of photographic film to detect visible light and beta and gamma radiation from radioactive materials.

Each silver halide salt has a different sensitivity to light.

When radiation hits the film the silver ions in the salt are reduced by electron gain to silver

Ag+ + e- ==> Ag, the halide ion is oxidised to the halogen molecule 2X- ==> X2 + 2e-

AgI is the most sensitive and used in X-ray radiography, AgCl is the most sensitive and used in 'fast' film for cameras."

taget fra:
http://www.wpbschoolhouse.btinternet.co.uk/page03/3_31rates.htm