The maximum contaminant level of fluoride (F−) in drinking water as set by the the Environmental Protection Agency (EPA) is 0.0040 g⋅L−1 . Express this concentration in parts per million (ppm). Assume the density of water is 1.00 g/mL .

1) describe the physical layout of the ocean floor ? 2) explain how the dumbo octopus swims differently than other octopus species and why this would be an advantage in the aphonic zone . 3) why are the types of organisms that live at each underwater hot vent so dramatically different ?