4. Assertion : Glassy solids have sharp melting point. Reason : The bonds between the atoms of glassy solids get broken at the same temperature.

(a)        If both assertion and reason are true and the reason is the correct explanation of the assertion.

(b)        If both assertion and reason are true but reason is not the correct explanation of the assertion.

(c)        If assertion is true but reason is false.

(d)        If the assertion and reason both are false.

(e)        If assertion is false but reason is true.

Explanation-

(d) In a glassy solid (e., amorphous solid) the various bonds between the atoms or ions or molecules of a solid are not equally strong. Different bonds are broken at different temperatures. Hence there is no sharp melting point for a glassy solid.

(13)