A. Archilles ! Hope this helped :)!
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 
Answer:
1750L
Explanation:
Given
Initial Temperature = 25°C
Initial Pressure = 175 atm
Initial Volume = 10.0L
Final Temperature = 25°C
Final Pressure = 1 atm
Final Volume = ?
This question is an illustration of ideal gas law.
From the given parameters, the initial temperature and final temperature are the same; this implies that the system has a constant temperature.
As such, we'll make use of Boyle's Law to solve this;
Boyle's Law States that:
P₁V₁ = P₂V₂
Where P₁ and P₂ represent Initial and Final Pressure, respectively
While V₁ and V₂ represent Initial and final volume
The equation becomes
175 atm * 10L = 1 atm * V₂
1750 atm L = 1 atm * V₂
1750 L = V₂
Hence, the final volume that can be stored is 1750L
A coordination number can be determined by the usage of an atom towards a molecule from seeing how many numbers of atoms would have to be combined together in an atom.
Answer: 27 neutrons
Explanation:
Recall that the number of protons in the nucleus of an atom = Atomic number.
Hence, Calcium with mass number 47 and atomic number 20 will have 20 protons
Therefore, since Mass number = number of protons + neutrons
47 = 20 + neutrons
Neutrons = 47 - 20 = 27
Thus, there are 27 neutrons in radioactive calcium nucleus.