What can the arrow in a chemical reaction be translated to mean? check all that apply.

The ardor determines the result of a reaction.
[formula A]+[formula B]—> [formula C]
Here, the arrow signifies that when adding formula A and B, you get formula C. An arrow can also go both directions.
[formulaA]+[form.B]<—>[formulaC]+[form.D]
Here, the double sided arrows means that adding formulas A and B will give you C and D, and adding formulas C and D will give you A and B.

The purpose of a lab is to do your "expirements" the importance of the topic is so you can now what the story is about and the last one is because no one is me with my question ( what is 3 over 4 x - 9 = 27 maybe you can )

Answer(a)   the matererials that are in contact, the two materials and the nature of their surfaces/// (b)/// the force pushing the two surfaces together, pushing the surfaces together causes the more of the asperities to come together and increases the surface area in contact with each other