The instrument used is a microscope. This has a number of lens, for instance, you can choose to magnify the cell or whatever it is x4/x10/x40.
Hope this helps :)
microscope
they used it
A microscope is a common tool used by scientists to explore living things. It allows for magnification and visualization of cells, tissues, and organisms at a microscopic level. By using a microscope, scientists can study the structure and function of living organisms in detail.
Einstein was a theorist, and as such, used only his mind.
thermometer
Microscope.
computer
graphs
Calculus
carbon dating
A tool is an object used for doing work such as building or repairing things.
soap