Question

a scientist is examining the role of an element found in fats and carbohydrates of living things. this element makes up 65% of human body mass. which statement describes the element he is studying? he is studying oxygen, which can also be found in proteins. he is studying oxygen, which is the most abundant element in the atmosphere. he is studying nitrogen, which can also be found in proteins. he is studying nitrogen, which is the most abundant element in the atmosphere.

Explanation:

1. Recall the composition of the human body: Oxygen makes up about 65% of human body mass and is present in fats, carbohydrates, and proteins.
2. Analyze the options:

• The most abundant element in the atmosphere is nitrogen (about 78%), so options with "most abundant in atmosphere" for oxygen are wrong.
• Nitrogen is not 65% of body mass, so nitrogen - related options are wrong.
• The first option correctly states oxygen is in fats, carbs, proteins and is 65% of body mass.

Answer:

A. He is studying oxygen, which can also be found in proteins.