Question

how can we detect atoms even though we cannot see them with our eyes? blowing up a balloon measuring temperature changes compressing air in a syringe using a microscope

Explanation:

Blowing up a balloon and compressing air in a syringe show the presence of air particles (made of atoms and molecules) through volume - related changes, but they don't directly detect atoms. Measuring temperature changes is not a way to detect atoms. Using a powerful microscope like a scanning tunneling microscope can detect atoms by interacting with the electrons on the surface of materials.

Answer:

Using a microscope