On exposure to air, sodium hydroxide becomes liquid and after sometime it changes to white power. Explain.

Discuss why on exposure to air, sodium hydroxide becomes liquid and after sometime it changes to white powder.

On prolonged exposure to air, sodium finally changes to

Why do silver articles become black after sometime when exposed to air ?

Why do silver articles become black after sometime when exposed to air ?

On prolonged exposure to air, sodium finally change to :

On prolonged exposure to air, sodium finally changes to:

On prolonged exposure to air, sodium finally change to :

On prolonged exposure to air, sodium finally change to :

A stirred liquid comes to rest after sometime. Why?