The soldiers of Napoleon army while at Alps during freezing winter suffered a serious problem with regard to the tin buttons of their uniform. White metallic tin buttons get converted to grey poweder. This transformation is relate to

Options

A. A change in the partial pressure of oxygen in the air
B. A change in the crystalline structure of tin
C. An interaction with nitrogen of the air at very low to temperature
D. An interaction with water vapour contained in the humid air

Answer

B

Explanation

Grey tin is very brittle and easily crumbles down to a powder in very cold climates.
`underset("(Cubic)")("Grey in") hArr underset("(Tetragonal)")("White tin")`
The change of white tin to grey tin is accompanied by increases in volume. This called tin disease or tin plague.