Assume you are looking for microorganisms in a tissue sample from a lung biopsy. the microbes become apparent when you switch to 100x. what microbes is most likely?

Magnification can be illustrated as the amplification in the size of an object, in appearance. This is attained with the help of lenses present in the compound microscope. It is signified in terms of X, for example, of the lenses can magnify at 10 times, the magnification of the lens will be expressed as 5X.  

The magnification power of the eyepiece is 10X, but distinct kinds of objective lens, with different magnifying power, is used, in order to, increase the magnification.  

So, to attain the resolution of 100X, the eyepiece having 10X magnifying tendency is used in collaboration with an objective lens of 100X, in such magnification, the most possible kind of microbes that can be visualized is a bacterium.