# Question Video: Explaining the Difference between the Resolution of Light and Electron Microscopes Biology

Which of the following best explains the difference in resolution between light and electron microscopes? [A] Electron microscopes have a higher resolution, as they use beams of electrons with short wavelengths. This makes it easier to distinguish between different structures. [B] Light microscopes have a higher resolution, as they use waves of light with long wavelengths. This makes it easier to distinguish between different structures.

02:22

### Video Transcript

Which of the following best explains the difference in resolution between light and electron microscopes? (A) Electron microscopes have a higher resolution, as they use beams of electrons with short wavelengths. This makes it easier to distinguish between different structures. (B) Light microscopes have a higher resolution, as they use waves of light with long wavelengths. This makes it easier to distinguish between different structures.

To understand how to answer this question, let’s first review what resolution means. Resolution is the minimum distance required between two adjacent objects for them to be distinguished as individual separate objects. It is measured in nanometers. If two objects cannot be resolved, they will be seen as one object under a microscope.

Light microscopes and electron microscopes use different sources of illumination. Light microscopes use light, and electron microscopes use electrons. The wavelength of the illumination source contributes to the resolution. Here we can see a wave of light with its wavelength indicated. The wavelength of this light is 400 nanometers, but the wavelength of light can range from 400 to 700 nanometers. On the other hand, electron microscopes use a beam of electrons. The wavelength of an electron beam is much shorter than the wavelength of light, at about one nanometer.

One of the factors affecting resolution is the wavelength of the source of illumination that’s being used. The best light microscopes can resolve images up to around 200 nanometers apart, which is half of its shortest wavelength. You can see here that these two objects are not resolved by light because they’re less than half the wavelength of light away from each other. On the other hand, the same two objects placed the same distance from each other with an electron microscope would be resolved. This is because the wavelength of an electron beam is much shorter than the distance between the two objects.

Therefore, going back to our question, the option that best explains the difference in resolution between light and electron microscopes is given by answer choice (A). Electron microscopes have a higher resolution, as they use beams of electrons with short wavelengths. This makes it easier to distinguish between different structures.