interact verb [I]. âº to âcommunicate with or âreact to each other: He does not interact well with the other âstudents. interaction noun [C/U] us /ËÉªnÂ·tÉrËaekÂ·tÉrËÃ¦k/ âº [ÊÉn] âc drug. interactions [Noun/C] u /usÂ·ËÉªnÂ·tÉrËaek/. tÉrËÃ¦k ÊÉn
Scientists estimate a safe oxygen consumption of 50 liters per hour for a human. Meanwhile, a leaf gives off about five milliliters of oxygen per hour. A person would need to be in a room with about ten thousand leaves. About 300 to 500 plants would produce the right amount of oxygen.
Most of this oxygen comes from tiny ocean plants â called phytoplankton â that live near the waterâs surface and drift with the currents. Like all plants, they photosynthesize â that is, they use sunlight and carbon dioxide to make food. A byproduct of photosynthesis is oxygen. Scientists believe that phytoplankton contribute between 50 to 85 percent of the oxygen in Earthâs atmosphere. They arenât sure because itâs a tough thing to calculate. In the lab, scientists can determine how much oxygen is produced by a single phytoplankton cell. The hard part is figuring out the total number of these microscopic plants throughout Earthâs oceans.