The electron microscope has a maximum magnification of 250 000X and a resolving power of about 7 x 10-7 mm. How many times better is the resolution of the electron microscope than the best light microscope?
The Correct Answer and Explanation is:
To determine how many times better the resolution of an electron microscope is compared to the best light microscope, we need to compare their resolving powers.
- Electron microscope resolving power: 7×10−77 \times 10^{-7}7×10−7 mm
- Best light microscope resolving power: typically around 2×10−42 \times 10^{-4}2×10−4 mm
Now, divide the light microscope’s resolving power by that of the electron microscope:2×10−47×10−7=27×103≈0.2857×103=285.7\frac{2 \times 10^{-4}}{7 \times 10^{-7}} = \frac{2}{7} \times 10^{3} \approx 0.2857 \times 10^{3} = 285.77×10−72×10−4=72×103≈0.2857×103=285.7
Answer: The electron microscope has approximately 286 times better resolution than the best light microscope.
Explanation
Microscopes are essential tools in biology and materials science because they allow us to observe objects too small to be seen with the naked eye. Two critical specifications of any microscope are magnification and resolving power. Magnification refers to how much larger the image appears compared to the actual object. However, magnification alone is not enough to see fine details. Resolving power, or resolution, is the ability of a microscope to distinguish two points as separate. The smaller the resolving power value, the better the microscope is at revealing fine detail.
The electron microscope uses a beam of electrons instead of visible light to illuminate specimens. Electrons have much shorter wavelengths than light, which allows for significantly higher resolving power. In this case, the electron microscope has a resolving power of about 7×10−77 \times 10^{-7}7×10−7 mm. In contrast, the best light microscopes, which are limited by the wavelength of visible light, have a resolving power around 2×10−42 \times 10^{-4}2×10−4 mm. By dividing the resolving power of the light microscope by that of the electron microscope, we find that the electron microscope is roughly 286 times better at resolving fine detail.
This difference in resolution means that electron microscopes can reveal structures inside cells, such as organelles and viruses, which are impossible to see with light microscopes. This ability is crucial in fields like microbiology and nanotechnology, where understanding structures at the molecular or atomic level is important.
