In a particular mass of kau(cn)2, there are 6.66 × 1020 atoms of gold. what is the total number of atoms in this sample?

Total number of atoms in the sample is the sum of number of atoms of all the elements present in the sample.

Number of gold, atoms in = atoms     (given)

From the formula of compound that is it is clear that the number of potassium and gold are same whereas those of carbon and nitrogen are 2 times of them.

So, the number of atoms of each element is:

Number of potassium, atoms in = atoms    

Number of carbon, atoms in = atoms =

Number of nitrogen, atoms in = atoms =

Total number of atoms in = Number of gold, atoms+Number of potassium, atoms +Number of carbon, atoms + Number of nitrogen, atoms

Total number of atoms in =

Total number of atoms in = atoms

Hence, the total number of atoms in is atoms.

if you're asking what comes out, it's steam.