Which carbohydrate structure contains equal numbers of carbon and oxygen atoms while having twice as many hydrogen atoms?

The correct answer is monosaccharide because monosaccharides, which are the simplest form of carbohydrates, have the molecular formula ( C_n(H_2O)_n ). This means that for every carbon atom, there is one water molecule's worth of hydrogen and oxygen atoms combined, which translates to equal numbers of carbon and oxygen atoms, and twice as many hydrogen atoms.

Monosaccharides, such as glucose and fructose, exemplify this structure clearly, containing the ratio of 1:2:1 of carbon, hydrogen, and oxygen. This foundational structure sets monosaccharides apart from the more complex carbohydrates like disaccharides, polysaccharides, and oligosaccharides, which are formed by the bonding of monosaccharides and have more complicated ratios of these elements. Thus, understanding the structure of monosaccharides is crucial for grasping the broader concepts in carbohydrate chemistry.