Answer:
oxygen is an element and water is a compound
Explanation:
oxygen is made up of two atoms and water is made up of two elements
Answer:
2.7 billion
Explanation:
This period is referred to as the Great Oxygenation Event. This period saw the evolution of photosynthetic organisms (cyanobacteria) that utilized carbon dioxide (that dominated the atmosphere then) and sunlight to manufacture their energy molecules-glucose. Photosynthesis produces oxygen as a byproduct that is evolved into the atmosphere. As these photosynthetic organisms proliferated on earth, the atmosphere composition changed to become partly dominated by oxygen (which is an oxidaton agent) with less and less carbon dioxide.
Biomass is the total mass of a specific organism in the area. If there is a negative value of change in shoot biomass, that mean the mass of the shoot in this period are less than before. This indicate increases in predation/death which reduce the population of the shoot more than its growing rate. The cause could be an increases in predator population or decreases in food/resource.
D. Carbon moved in a cyclic fashion through the atmosphere and living organisms