Question

Why have scientist devised a system of comparative weights for atoms rather than using actual weights

Answer 1

Because of multiple reasons:

Step-by-step explanation:

1. Atoms are way too small to weigh.
2. They couldn't use weight, they would have to use mass.
3. Some atoms are free-floating, because they are the air.
4. If they even made a scale that measured each atom, it would also catch the air atoms as well, unless they had a vacuum chamber, but even then, no one can make a perfect vacuum, space is not even a perfect vacuum...

Hope this helps.