In a neutral compound, the sum of the oxidation states is zero. note that the sign of the oxidation states and the number of atoms associated with each oxidation state must be considered. in h2o, for example, each hydrogen atom has an oxidation state of 1 and each oxygen atom has an oxidation state of −2 for a total of 2( 1) (−2)

1.solid

2.carbon dioxide

3.helium

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.

your answer would be “dry”