what are the products of the
alkali metals in a reaction with:
oxygen, water, halogen?

Using The element calcium Ca, we have

CaO

CaOH

CaCl

Explanation:

i think a, hope it .

explanation:

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.