What happens in a synthesis reaction? A. Two substances combine to form a single new substance.
B. One substance breaks down into two substances.
C. One substance separates into ions in solution.
D. Atoms in two substances rearrange to form new substances.

A synthesis reaction is reaction in which two or more reactants combines with each other to form a single product.

So, Correct Answer is :

A. two substances combine to form a single new substance.

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.

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.