Copper (II) Carbonate + Heat yields copper (II) oxide and carbon dioxide
Molecular Equation: CuCo3 + heat > CuO + CO2
Answer:
two negative charges is the answer of your question
1. NA = Sodium, NA was the chemicals symbols for the element would be NA because in Latin it is natrium for natron in which is sodium in English, Sodium was created by Humphry Davy in the year of 1807. Element name Sodium, Chemical symbol NA atomic number, 11 Atomic mass 23.
2. AG = Sliver, AG was the chemicals symbols for the element would be AG because in Latin it is argentum in which in English means bright and also sliver. Element name Sliver Chemical symbol AG atomic number, 47 Atomic mass 108.
Density is equal to mass divided by volume so the densest object will be the object that has the largest mass in the smallest area.
In this case object A is the densest with a density of 10g/cm^3.
I hope this helps. Let me know if anything is unclear.