5. Complete Activity 5.5 (Page 53).
• Find out about electron microscopes from resources in the school library or through the internet. Discuss it with your teacher.
Answer:
Introduction: An electron microscope is an instrument used in scientific research to visualize structures at a very high resolution. Electron microscopes use a beam of electrons instead of light (used by traditional optical microscopes) to achieve much higher magnification and resolution. This allows the observations of structures at the nanoscale and has resulted in many ground-breaking discoveries.
Operating Principle: An electron microscope works by directing a beam of electrons at a sample. Depending on how the electrons interact with the specimen (scattered or absorbed), an image of the specimen is formed. Electron microscopes are of two types:
Transmission electron microscopes (TEM): TEMs pass electrons through a thin sample and produces detailed 2-D images of the internal structures. In biology, this technique can be used to study the internal structure of cells such as cell organelles.
Scanning electron microscopes (SEM): SEM scans the surface of a sample with a focused beam of electrons. The electrons interact with the sample surface in several ways, which generates a 3-D image of the surface. In conclusion, electron microscopes have empowered us to study specimens at the nanoscale in greater detail and with greater accuracy than traditional microscopes.
“Find out about electron microscopes from resources in the school library or through the internet. Discuss it with your teacher.” – Solved.
Related Links:
Solution to Activity 5.1
Solution to Activity 5.2
Solution to Activity 5.3
Solution to Activity 5.4
Solution to Activity 5.5
Solution to Activity 5.6
Solution to Activity 5.7
Solution to Chapter 5 The Fundamental Unit of Life
