Interdependence. Interdependence is a key idea in science. As students learn about science, they begin to understand that the earth is not a group of discrete parts but a continuous environment existing over time as well as place.
In order to remove the caffeine from coffee beans, the beans are washed in a solvent (a liquid capable of dissolving substances), transferring the caffeine from bean to liquid in a process known as extraction. To extract caffeine from whole coffee beans, the following solvents can be used:
The researchers found that while Starbucks didn't have the highest average caffeine amount, they did have the most consistent amount of caffeine per ounce of brewed coffee, at 17 milligrams per ounce. Meaning, you might not be getting the biggest bang for your buck caffeine-wise, but you're much more likely to get the same caffeine dose every time.