What is a pure substance with only one atom called

How many atoms are there in 5.70 mol of mg

What term describes technology that operates on an atomic level

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 ?