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. an interaction with nitrogen of the air at very low temperatures
B. a change in the crystalline struture of tin
C. a change in the partial pressure of oxygen in the air
D. an interaction with water vapour contained in the humid air

Answer

B

Explanation

Transitin of white to grey tin occurs at any temperature below `15.2^(@)C`, it becomes rapid at `-50^(@)C` . The conversion of white tin to grey tin (as in cold countries) is accompanied by an increases in volume and the latter, being very brittle, easily crumbles down to powder (a charge in crystallines structure of tin).