Quizlet is a great flashcard site that helps you create your own flashcards, and provides you with some great ready-made flashcards as well. As an ESL teacher, I find it to be very useful, especially for students who are not native speakers and do not have anybody at home to help them with their vocabulary.
The atmosphere, the ocean, and the terrestrial biosphere. Carbon can be found in the earths oceanic and continental crust in different types of stones as well as in the soil from the decay of organic matter.
Big quantities of carbon are found in the form of compounds. Carbon is present in the atmosphere as carbon dioxide in 0,03% in volume. Several minerals, like limestone, dolomite, gypsum and marble, contain carbonates. All the plants and live animals are formed by complex organic compounds where carbon is combined with hydrogen, oxygen, nitrogen and other elements.