Atoms and molecules are way too small to be seen even with a microscope so it can be counted by mass.
According to the context, the term actually may or may not encompass ions that meet this requirement. A molecule would be a collection of more than two atoms held together through attractive forces described as chemical bonds.
Atoms are incredibly tiny, with a diameter of around 1 x [tex]10^{-10}[/tex] meters. They can't be seen with a light microscope due to their small size. The composition of atoms can be observed and studied using a variety of ways, even if a light microscope might not be able to see one atom.
Therefore, atoms and molecules are way too small to be seen even with a microscope so it can be counted by mass.
To know more about molecules
https://brainly.com/question/19922822
#SPJ4
