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:
Still, his body is dependent on the caffeine kick from those two mugs. As long as he gets one cup of coffee in the a.m., he's generally headache-free. Trust me; I've spent many a morning on vacation tracking down a coffee source for him. The truth is that there are lots of ways to get your caffeine fix. Some of the people chugging down those Big Gulps all afternoon may be in it for the caffeine. Another popular way to get caffeine is tea, hot or iced. A can of diet cola (or similar) will give you around 42 milligrams of caffeine, while a cup of hot tea usually has almost 50 milligrams. I'm afraid eating chocolate can't compete with the caffeine power of a cup of Joe.