Question

Approximately what fraction of the mass of the human body is oxygen?
A.$\dfrac{1}{3}$
B.$\dfrac{1}{4}$
C.$\dfrac{2}{3}$
D.$\dfrac{3}{4}$

Answer 1

Hint: The makeup of one's body may be measured in a variety of ways. Water, protein, fats (or lipids), hydroxylapatite (in bones), carbohydrates (such as glycogen and glucose), and DNA are examples of chemical components that may be identified. The body can be classified as water, fat, connective tissue, muscle, bone, and other tissue types. The human body includes hundreds of different types of cells, but the highest number of cells (albeit not the biggest quantity of cells) are bacteria found in the typical human gastrointestinal system.

Complete answer:
Six elements make up about 99 percent of the mass of the human body: oxygen, carbon, hydrogen, nitrogen, calcium, and phosphorus. Only 0.85% of the total is made up of the following five elements: potassium, sulphur, sodium, chlorine, and magnesium. All 11 are required for survival. The remaining elements are trace elements, of which more than a dozen are considered to be essential for life based on strong evidence. The mass of all 11 non-trace elements combined (less than 10 grammes for a human body) does not equal the mass of magnesium, the least common of the 11 non-trace elements. 65 percent oxygen, 18.5 percent carbon, 9.5 percent hydrogen, and 9.5 percent nitrogen (3.3 percent). These elements aren't present in pyrotechnics, but they are numerous and vital compounds in human bodies, such as water, proteins, and DNA.
Oxygen, which makes up around 65 percent of the human body's mass, makes up the majority of its bulk. This makes up two-thirds of the body's bulk.
Hence option C is correct.

Note:
Individuals differ in their proportional quantities of each element, owing to variations in the proportions of fat, muscle, and bone in their bodies. People who are more obese will have a greater carbon content and a lower content of most other elements (the proportion of hydrogen will be about the same). The figures in the table are averages of various figures provided by various sources.