Question

The contact angle between a solid and a liquid is a property of
(a) the material of the solid
(b) the material of the liquid
(c) the shape of the solid
(d) the mass of the solid

Answer 1

The contact angle between liquid drop and solid surface is dependent on the nature of the liquid as well as the surface characteristics of the solid.  

Explanation:

The contact angle between a liquid and a solid is the angle within the drop of the liquid formed at the gas–liquid–solid interface. This can be determined by drawing a tangent on liquid drop from the contact point of liquid, solid and gas interface. it provides information about the wettability of an ideal surface.

If the contact angle is less than $90\°$, then liquid will wet the surface and spread over it completely. If the contact angle is greater than or equal to $90\°$, then liquid drop will stay on the surface as a bead and moves on a surface as ball.

Hence, the contact angle between liquid drop and solid surface is dependent on the nature of the liquid as well as the surface characteristics of the solid.  

Answer 2

Answer:

Both the material of solid and liquid