The phenomenon of water beading up on a surface and forming a drop is due to the water's
a. corrosion
b. obtrusion
c. adheison
d. cohesion

C.Adheison

Explanation:

Let's begin by understanding the following definitions:

Cohesion  

Is the attraction that molecules have for others of their same type.

Adhesion  

Is the attraction that molecules have for others of different type by intermolecular forces.  

In this sense, water have both properties, it can stick to itself through hydrogen bonds (cohesion) and can also stick to a glass (or a surface) due to adhesion.  

So, while Cohesion is the force of attraction between water particles and the responsible of forming water drops, Adhesion is the interaction between water particles and the surfaces.

Therefore, when water drops stick to the surface is due adhesion.  

answer: the rock sample is a sedimentary rock.

explanation:

it is given that:

mass of rock sample, m = 2.7 g

volume of rock sample,

so, density of rock sample will be

since, the density of rock sample is . hence, the rock sample is a sedimentary rock, whose densities varies between .

answer;

d. are made mostly of liquid

explanation;

-the general   composition and structure planets includes; they have a thick gas and liquid layer covering a small,solid core. mostly the gases are hydrogen and helium atmosphere and layers of liquid hydrogen. for instance neptune and uranus are examples of the outer planets, they have a core covered by ice and ammonia.

-neptune's atmosphere is hydrogen and helium with a bit of methane so there is no oxygen to breath and the interior is made up of frozen water and ammonia with a rock and iron core. thus, there is no liquid water or solid surface to survive.