What happens when?a) Silver nitrate comes in contact with skin( organic matter) in presence of lightb) Silver nitrate is heated

a)When silver nitrate comes in contact with skin, it is reduced to white color metallic silver.In most cases, a black stain appears due to formation of finely divided silver which has black color.

The black color is due to the decomposition of the Ag+ ion into Ag, silver. Silver nitrate will slowly decompose with the silver ion reverting to elemental silver. The microscopic particles of silver are so small that they absorb light instead of reflecting it, and so appear black, instead of silver....

Write chemistry of lunar caustic

Silver nitrate is called lunar caustic because when it comes in contact with organic substances (e.g., skin , clothes) and reduced to metallic silver which is white like the iron lunar.

Silver Nitrate is a salt, which is colorless or of a white crystalline form. When this is exposed to light or any organic material, this becomes black in color. Silver Nitrate when heated decomposes and forms, Silver, Nitrogen dioxide and Oxygen.

2 AgNO3 2 Ag + 2 NO2 + O2

Write any three physical properties of the given metals.

a.    Iron:
    > It is good conductor of heat.
    > Its specific gravity is 7.86.
    > It is malleable and ductile.
b.    Aluminium:
    > It is good conductor of heat and electricity.
    > its specific gravity is 2.7.
    > It is highly malleable and ductile.
c.    Copper:
    > It is good conductor of heat and electricity.
    > its specific gravity is 8.95.
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