We can use the given mass of a single nickel atom and the mass of the sample to calculate the number of nickel atoms in 211 milligrams of nickel.
First, we can convert the mass of the sample from milligrams to grams:
211 milligrams = 0.211 grams
Next, we can use the mass of a single nickel atom to calculate the number of atoms in the sample. We can use the following conversion factor:
1 atom / 9.75×10^-23 grams
Multiplying the mass of the sample by this conversion factor, we get:
0.211 grams * (1 atom / 9.75×10^-23 grams) = 2.16×10^20 atoms
Therefore, there would be approximately 2.16×10^20 nickel atoms in 211 milligrams of nickel.