Question

The change of source of illumination from light to electrons significantly improved the \(\underline{\hspace{2cm}}\) of the microscope. 
 

• A. Resolving power
• B. Resolution
• C. Numerical aperture
• D. Magnification

Hint:

Think of it this way: Resolution/Resolving Power is about clarity, while Magnification is about size. You can magnify a blurry image, but it just gets bigger and blurrier. The switch to electrons improved the fundamental clarity (resolving power), which then made higher magnifications meaningful.

Answer 1

The Correct Option is A

Step 1: Core Idea:
The prompt focuses on the key microscope characteristic enhanced by using electrons instead of light for illumination.

Step 2: Breakdown:
A microscope's resolving power, or resolution, is its capacity to differentiate between closely positioned points. This is fundamentally linked to the wavelength of the illumination source, as expressed by the Abbe diffraction limit. This limit states that the smallest discernible distance (d) is directly related to the wavelength (\(\lambda\)).\[ d \propto \lambda \]Electrons possess a substantially smaller de Broglie wavelength compared to photons of visible light. Substituting light with electrons reduces the wavelength (\(\lambda\)) of the illumination by many magnitudes. This reduction dramatically lowers the minimum resolvable distance (d), thus greatly improving the microscope's capacity to visualize fine details; this capacity is known as resolving power.
Although magnification also increased, improved magnification is only beneficial if resolving power is high enough to make magnified details clear. The primary enhancement was in resolution, and resolving power directly measures this ability.

Step 3: Conclusion:
The switch from light to electrons as the illumination source primarily enhanced the microscope's resolving power.