There are 7.3 x 10²² atoms Cd.
The mole can be used to relate masses of substances to the quantity of atoms therein. This is an easy way of determining how much of one substance can react with a given amount of another substance.
From moles of a substance, one can also find the number of atoms in a sample and vice versa. The bridge between atoms and moles is Avogadro's number, 6.022×10²³.
Avogadro's number is typically dimensionless, but when it defines the mole, it can be expressed as 6.022×10²³ elementary entities/mol. This form shows the role of Avogadro's number as a conversion factor between the number of entities and the number of moles. Therefore, given the relationship 1 mol = 6.022 x 10²³ atoms, converting between moles and atoms of a substance becomes a simple dimensional analysis problem.
Studying chemistry can be stressful and feel overwhelming. There is no magic formula for learning chemistry, but you can develop an effective strategy for success.
Whether you're in middle school, high school or college, these simple steps will get you on the right track. Basically it involves not getting behind, doing your own work, and not psyching yourself out.