Answer:
A disproportionation reaction is when a multiatomic species whose pertinent element has a specific oxidation state gets oxidized and reduced in two separate half-reactions, yielding two other products containing the same pertinent element. A convenient example is Mn2O3 becoming Mn2+ and MnO2 .
The planet Earth itself is considered to be a closed system because there is a limit to the amount of matter that is exchanged. However, there are open systems that are ON Earth.
One-
The 6 is the only significant figure.
