Oxygen gas was most likely absent from Earth's primitive atmosphere. The current theory is that the Earth's early atmosphere was composed of mainly carbon dioxide and methane due to the high volcanic activity. Cyanobacteria and their use of photosynthesis was what caused earth's atmosphere to become oxygen enriched.
I hope that helps.
A pure chemical compound is a chemical substance that is composed of a particular set of molecules or ions that are chemically bonded.
Answer:
0 net force it is balanced
Explanation:
If the amount of force is the same on both sides the net force equals 0
The statement that best explains why heating a liquid affects its viscosity is that "The molecules move faster at higher temperatures and overcome attractions more easily."<span>. Remember that viscosity is a physical property of the fluids that measure the resistance (opposition) to flow and it, generally decreases, as the temperature increases and the intermolecular force decrease.</span>
