Answer:
Core is the densest layer of the earth.
Explanation:
The structure of the earth's interior is made up of several concentric layers. The earth's interior is divided into three layers- The Crust, the mantle and the core. The density of the outermost layer the crust is 3 g/cm^3. As we move towards the interior, the earth become more dense. The density of the second layer mantle ranges between 2.9-3.3 g/cm^3. The core is the innermost layer of the earth, surrounding the earth's center. the density of the core ranges between 9.5-14.5 g/cm^3.
Answer:
oxygen: it was the result of biological activities. There were such stable continental shelf environments, which were rare in the Archean, developed after 2.5 billion years ago, facilitating the growth of photosynthetic organisms and thus oxygen production.
The answer would be B) Nitrogen Trioxide
Main source of energy for reactions that occur in all living organisms is ATP.