Ask Question
18 June, 00:08

To resolve an object in an electron microscope, the wavelength of the electrons must be close to the diameter of the object. What kinetic energy, E k, must the electrons have in order to resolve a protein molecule that is 2.70 nm in diameter? Take the mass of an electron to be 9.11 * 10 - 31 kg.

+1
Answers (2)
  1. 18 June, 00:16
    0
    3.32 * 10^-20 J

    Explanation:

    Let the wavelength of the electron be equal to the diameter if the protein molecule.

    λ = 2.7 * 10 ^ - 9 m

    using De Broglie's equation

    λ = h / mv

    Where

    λ = wavelength

    h = Planck's constant

    m = mass of the particle

    v = velocity of movement of the particle

    Then ...

    v = h / mλ

    v = (6.63 * 10^-34) / [ (9.11 * 10^-31) * (2.7 * 10^-9) ]

    v = 2.70 * 10^5 m/s

    KE = Kinetic Energy

    KE = 1/2mv²

    KE = 1/2 (9.11 * 10^-31) * (2.7 * 10^5) ²

    KE = 3.32 * 10^-20 J
  2. 18 June, 00:32
    0
    KE = 3.308*10^-20J

    Explanation:

    Let the wavelength of the electron equal the diametre of the protein molecule

    Wavelength = 2.70 nm = 2.70 * 10^-7m

    The de Brogule expression gives ud:

    Wavelength = h / mv

    V = h/m * wavelength

    Where h is plank's constant

    V = (6.63*10^-11) / (9.11*10^-31) (2.70*10^-9)

    V = (6.63*10^-34) / (2.4587*10^-30)

    V = 2.695*10^5m/s

    KE = 1/2mv^2

    KE = 1/2 (9.11*10^-31) (2.695 * 10^5) ^2

    KE = 1/2 * (9.11*10^-31) (7.26*10^10)

    KE = 3.308*10^-20J
Know the Answer?
Not Sure About the Answer?
Find an answer to your question 👍 “To resolve an object in an electron microscope, the wavelength of the electrons must be close to the diameter of the object. What kinetic ...” in 📗 Physics if the answers seem to be not correct or there’s no answer. Try a smart search to find answers to similar questions.
Search for Other Answers