Chapter 20, Problem 1RQ

What are the two most abundant elements by mass in the earth’s crust, oceans, and atmosphere? Does this make sense? Why? What are the four most abundant elements by mass in the human body? Does this make sense? Why?

Interpretation Introduction

Interpretation: The two most abundant elements by mass in the Earth's crust, oceans and atmosphere are to be stated with a valid explanation. Also, the four most abundant elements by mass in the human body are to be stated with a valid explanation.

Concept introduction: The element that has the highest concentration (by mass) on the Earth is known as the most abundant element of the Earth.

To determine: The name of the two most abundant elements by mass in the Earth's crust, oceans and atmosphere with valid explanation; the name of the four most abundant elements by mass in the human body with a valid explanation.

Answer to Problem 1RQ

Answer

Oxygen and silicon are the two most abundant elements by mass in the Earth's crust, oceans and atmosphere.

Carbon, hydrogen, nitrogen and oxygen are the most abundant elements by mass in the human body.

Explanation of Solution

Explanation

Oxygen and silicon are the two most abundant elements by mass in the Earth's crust, oceans and atmosphere.

Yes, this makes sense. Earth’s crust contains silicon dioxide $\left({\text{SiO}}_{\text{2}}\right)$. Oxygen is present in the atmosphere in gaseous form, whereas it is present in the ocean in a liquid form

Carbon, hydrogen, nitrogen and oxygen are the most abundant elements by mass in the human body.

Carbon, hydrogen, nitrogen and oxygen are the most abundant elements by mass in the human body.

Yes, this makes sense. The human body contains greater amount of protein and amino acids.

The composition of protein is carbon, oxygen and nitrogen. The main composition of amino acid is carbon, oxygen, hydrogen and nitrogen.

Conclusion

Conclusion

Since, Earth’s crust contains the highest concentration of silicon dioxide and ocean contains the highest concentration of oxygen. Hence, oxygen and silicon are the two most abundant elements in the Earth’s crust and ocean.

Since, the human body is basically composed of carbon, oxygen, hydrogen and nitrogen. Therefore, these are the most abundant elements by mass in the human body