Monitoring and regulating nuclear waste generated and issues associated to it the US.
Answer: The green copper (II) carbonate
changes to black copper oxide 

Explanation:
Decomposition is defined as the chemical reaction in which a single compound gives two or more simple substances. It requires energy to break the bonds between reactants, thus is an endothermic process.
Thermal decomposition uses heat for decomposition.
The chemical equation for thermal decomposition of copper (II) carbonate is:

The green copper (II) carbonate
changes to black copper oxide 
Explanation:
Gold conducts heat and electricity. ...
Gold is ductile: It can be drawn out into the thinnest wire. ...
Gold is highly reflective of heat and light. ...
Gold is prized for its beauty. ...
Gold is malleable, so it can be flattened into extremely thin sheets.
on the other hand Gold consist of copper
Key Properties of Copper Alloys
Excellent heat conductivity.
Excellent electrical conductivity.
Good corrosion resistance.
Good biofouling resistance.
Good machinability.
Retention of mechanical and electrical properties at cryogenic temperatures.
Non-magnetic.
so the difference is that copper is less expensive and not priced with its beauty
Explanation:
Because when two equal forces are applied from opposite directions, they "eliminate" each other.
The train would go right if a 3N force was only applied in the right direction, and it would go left if the same force was only applied to the left.
If a 3N force was applied to the right and a 2N force to the left, it would equal a 1N force to the right (3-2=1).
But there it's 3-3=0, so in practice the force is 0N. Therefore the train won't move.
C. a chemical reaction occurred when the two liquids were mixed