Final answer:
For each carbon and oxygen in a carbohydrate, there are 2 hydrogen atoms, reflected in the 1:2:1 ratio in the carbohydrate formula (CH₂O)n, making the answer A. 2.
Step-by-step explanation:
In carbohydrates, for every 1 carbon and 1 oxygen atom, there are 2 hydrogen atoms present. This can be understood through the stoichiometric formula for carbohydrates, which is (CH₂O)n, where n is the number of carbon atoms in the molecule. Hence, the ratio is 1:2:1 for carbon to hydrogen to oxygen.
This formula also reveals the origin of the term “carbohydrate”: the elements are carbon (“carbo”) and the components of water (hence, “hydrate”). The correct answer to the question is A. 2.
Furthermore, carbohydrates are categorized into three types: monosaccharides, disaccharides, and polysaccharides. An example is glucose, a monosaccharide with six carbon atoms, twelve hydrogen atoms, and six oxygen atoms, which are arranged in the ratio defined by the carbohydrate formula.