<span>Carbon dioxide is a colorless and odorless gas that is vital to life on Earth. This naturally occurring chemical compound is made up of a carbon atom covalently double bonded to two oxygen atoms. Carbon dioxide exists in Earth's atmosphere as a trace gas at a concentration of about 0.04 percent by volume. Natural sources include volcanoes, hot springs and geysers, and it is freed from carbonate rocks by dissolution in water and acids. Because carbon dioxide is soluble in water, it occurs naturally in groundwater, rivers and lakes, in ice caps and glaciers and also in seawater. It is present in deposits of petroleum and natural gas.</span>
The answer is hydrogen bonds
I think the answer is DNA
A - Salinity because salinity is how much salt is in water and adding more would increase the salinity.
All three are bad for the environment because all three types release CO2 into the air and have throughout their constant usage helped with creating the greenhouse effect that traps heat and causes global warming. That's why clean energy is a necessity and people are developing harnessing wind and solar power.