Calculations test IB2

Name .................................

Constants

 

1a Write down the maximum energy of electrons as they strike the anode in a cathode ray tube in electron Volts when the anode voltage is 3000 Volts.

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b Convert the maximum electron energy to Joules.

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c Show that the maximum velocity of electrons in the cathode ray tube is 3.2x10⁷ m/s by using the kinetic energy relationship.

 

 

 

 

 

 

 

2 Supposing the particle in the tube was an alpha particle with two positive charges and the anode were made from tungsten with an atomic number of 74. Calculate the distance of closest approach of the alpha particle in a head on collision with the stationary tungsten nucleus.

The potential near a large positive point charge is given by ...

 

 

 

 

 

 

 

 

 

 

 

 

 

 

3 In Bohr's model of the hydrogen atom the electron is imagined to orbit the nucleus with a restricted set of particular energies.

... where n is an integer that runs from 1, 2 upwards.

 

a Find the energy (when n = 1) of the lowest energy electron orbit in Joules.

 

 

 

 

 

 

 

 

b Convert this energy to electron volts.

 

 

 

c Calculate the lowest four energy levels in electron Volts [n = 1, 2, 3 and 4] and sketch the energy level diagram of the hydrogen atom.