Which of the following substances would be the softest?

cuo

sic

c25h52

zn

The paraffin is the softest.  

Explanation:

The others materials, they have a bigger value of hardness in Mohs scale, like the CuO with a value of 3.5, the SiC with a value of 9, and Zinc with a value of 2.5.

in chemistry, adhesion and cohesion are attractive forces that exist between molecules. they hold the molecules together from each other. they are different in that adhesive force exists between molecules of different substance while cohesive force happens between molecules of same substance.

adhesion between water and glass causes water molecules at the edge of water and glass interface to climb up the wall in a narrow glass tube. this is called capillary action. cohesion is what gives glass its shape and causes water to form a droplet.

explanation: