Some people naturally have more or less blemishes than others because of genes
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

Ni (Nickel) is the best conductor, and in fact the only conductor, in that list
The alkali metals, which occupy group 1 of the periodic table. This is because the valence shells of these elements have only 1 electron, so easily form an ionic bond with a non-metal compound by donating this. A cation is formed by this donation, since there is one fewer electron orbiting the nucleus than there is in the atomic form - conversely an anion is formed when an atom gains an extra electron to become negatively charged.