Representations of Processes Main Concept: Physical and chemical processes can be depicted symbolically; when this is done, the illustration must conserve all atoms of all types.  

Representations of Processes Ways to Represent Change 1. example(s): 2. Conservation of Matter What it means and how we apply it

- Conservation of mass: in any change, mass is always conserved - Mass is neither created nor destroyed; missing mass can be accounted for somehow

- Various types of representations can show how matter is conserved during chemical and physical processes Symbolic representations Particulate drawings

- Conservation of matter allows us to do stoichiometry - Conservation of atoms allow us to: - calculate product masses given reactant masses - calculate reactant masses given product masses

- conservation of atoms helps us understand many chemical processes on the macroscopic scale - Examples include how atoms cycle through land, water, atmosphere, and living organisms.

carbon dioxide cellulose glucose hydrocarbons carbon dioxide carbonates bicarbonates

nitrogen DNA, proteins DNA, proteins ammonium nitrates nitrites