Question

Which of the following elements is NOT one of the six most common elects in living organisms?

A) hydrogen
B) nitrogen
C) oxygen
D) iron
E) carbon

Answer 1

Iron (D) is not one of the six most common elements in living organisms, which are hydrogen, carbon, nitrogen, oxygen, phosphorus, and sulfur.

Step-by-step explanation:

The element that is NOT one of the six most common elements in living organisms is iron (D). The six most common elements that are found in living organisms, also known as macronutrients, are: hydrogen (H), carbon (C), nitrogen (N), oxygen (O), phosphorus (P), and sulfur (S). These elements are essential for life as they are the main components of biological molecules like proteins, nucleic acids, carbohydrates, and lipids. Iron, while important, is considered a micronutrient required by living organisms in smaller amounts.