There are two different structural isomers for 2-butene. Single bonded carbon atoms allow for rotation around the C-C bond, however, placing a second bond (producing a double bond) between two carbon atoms stops the rotation around these atoms. How does this restriction of rotation give rise to two different structural isomers of 2-butene (cis/trans isomers). (Hint: consider cyclo compounds which also have cis/trans isomers.)

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.