The hypothesis that all modern humans descended from an African lineage is supported by the mitochondrial DNA evidence. The Eve hypothesis is the hypothesis that is based on the study of mirtochodrial DNA; that modern humans have a common female ancestor who lived in Africa around 200,000 years ago. It is also called African Eve hypothesis.
In an ecosystem, two factors are being classified which are the abiotic and the biotic factors. Both of these factors play an important role in order to balance the ecosystem and maintain the harmony of the living things therein. The environment includes the abiotic factors which are the sunlight, weather, water, air, and all other factors which are not living but contribute to the growth and development of the living ones. For example, plants cannot live without water, sunlight and carbon dioxide. The effects that humans have on the environment is both good and bad. Humans also play an important role in maintaining the environment, and they also have the capability to endanger it.
Density is measured in mass per volume thus C would be the answer.
2.17 g / cm³
Google said hydrogen so I'm guessing B. gases
