B.13C_Carbon_approaching – 02

A student group was standing in front of a dinosaur exhibit at the Natural Science Museum. Their museum guide held up a small piece of natural chalk. The guide asked if anyone could explain how the piece of chalk could contain carbon that was exhaled by a dinosaur. The students talk about the facts needed to answer the question. First, they must find out where chalk is found in nature. Next, they must investigate the processes that provide a path for carbon in the air to become carbon in the chalk. The museum guide gives the students a hint by telling them that natural chalk is made of a chemical compound called calcium carbonate.
Carbonate contains carbon. The students know that this is an important fact about chalk. Carbon is an essential element in all organisms. Carbon is the basic element in the molecular structure of all organisms. Plants need carbon to grow and reproduce. Animals obtain carbon by eating plants or other animals. Carbon compounds are a source of energy for living things.
Chalk is not a living thing. The students search for more facts to link chalk to living things. The museum guide stated that all the answers can be found in the museum. In the shell exhibit, the students were told that shells of marine animals are made of calcium carbonate. This fact connects the chalk to living things. The students turn their attention to the carbon in the air. The carbon cycle is a biogeochemical cycle.

The carbon cycle is a biogeochemical cycle. Carbon atoms move between living and nonliving factors. Living factors in the carbon cycle are all living things on earth. Nonliving factors are the air, bodies of water, rocks, and decomposed organic matter in soil.