The metallic lustre of metals is due to :

Options

A. they have a hard surface and light is reflected back
B. their crystal structure contains ordered arrangement of constituent atoms
C. they contain loosely bound electrons which absorb the photons and then re-emit
D. they are obtained from the minerals on which light has been falling for years

Answer

C

Explanation

NaOH being deliquescent absord water from atmosphere therefore strength of solution will decrease.