Answer:
1.325 x 10²⁴ Co atoms
Step-by-step explanation:
1 mol of any substance is made of 6.022 x 10²³ units, these units could be atoms making up elements of molecules making up a compound.
Therefore 1 mol of the element cobalt is made of 6.022 x 10²³ atoms of Co
so if 1 mol of Co contains - 6.022 x 10²³ atoms of Co
then 2.2 mol of Co contains - 6.022 x 10²³ /mol x 2.2 mol
number of Co atoms in 2.2 mol of Co is - 1.325 x 10²⁴ Co atoms