What is the formula for the compound formed by iron (II) ions and chromate ions? F Fez(CrO4)3
G Fe(CrO4)2
H FeCrO4
J Fez Cr04

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.

chemical digestion occurs in the stomach were hcl and pepsin forms chyme, the mouth in which salivary amylase breaks down starch to form bolus, and the small intestine specifically the duodenum.

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