Which element, represented by the symbol O, makes up the majority of the human body by mass?

• A. Carbon
• B. Oxygen
• C. Nitrogen
• D. Hydrogen

Answer: (B)

Verified step by step guidance

1. Identify the symbol 'O' as the chemical symbol for the element Oxygen on the periodic table.
2. Recall that the human body is primarily composed of several elements, with Oxygen, Carbon, Hydrogen, and Nitrogen being the most abundant.
3. Understand that Oxygen is a major component of water (H\_2O), which makes up a large percentage of the human body by mass.
4. Recognize that because water is so abundant in the body, Oxygen contributes the largest mass percentage compared to Carbon, Nitrogen, or Hydrogen.
5. Conclude that the element represented by 'O' and making up the majority of the human body by mass is Oxygen.