What is species definition

Liquid water turns into water vapor at which step in the water cycle

Consider the following reaction: 2h2 + o2 —> 2h2o a) what are the reactants in this reaction? b) what are the products in this reaction? c) how many molecules of oxygen are used in this reaction?

Consider the equation s + o2 ? so2. what is the product? question 3 options: s so 2 s + so 2 o 2