Answer:
The value is 
Explanation:
From the question we are told that
The molar mass of
is 
The total mass is
The uncertainty of the total mass is 
Generally the molar weight of calcium is 
The percentage of calcium in calcite is mathematically represented as


Generally the mass of each sample is mathematically represented as



Generally mass of calcium present in a single sample is mathematically represented as


The uncertainty of mass of a single sample is mathematically represented as



The uncertainty of mass of calcium in a single sample is mathematically represent

Generally the average mass of calcium in each sample is

Answer:
The reaction mentioned in the question is a decomposition reaction.
Explanation:
Decomposition reaction is a specific type of chemical reaction in which the reactant molecule undergo break down to generate its respective products.
NaCl ⇒ Na + Cl2
In the above reaction sodium chloride(NaCl) undergo decomposition or break down to generate Sodium(Na) and chlorine gas(Cl2).
A. India-southeastern Asia monsoons
You need to use Stoichiometry