1.   (a) The most abundant isotope of an element is represented by:

    How many protons, neutrons and orbital electrons are there in a neutral atom of this element?
        protons
        neutrons
        electrons                       

    (b) How is the nuclide that has one less proton than the above represented?

    (c)  If Y undergoes beta - decay how will the resultant new element N be represented?

    (d) If N absorbs an alpha particle how will the resultant new element M be represented?

    (e) (i) An isotope of hydrogen, whose nucleon number is 2, is called deutirium.  
              How many protons, neutrons and orbital electrons are there in a neutral atom of this element?

        proton
        neutron
        electron  

        (ii) Calculate the charge per unit mass, in C/kg^-1 for a deutirium, nucleus.
         x 10 ⁷    C/kg^-1
             

2  (a) Calculate the energy, in J, of a photon of wavelength x 10 ^-7 m
        x 10^-19 J

    (b) Calculate the speed of an electron which has the same wavelength of the photon in part (i).
          m/s

3 (a) When monochromatic light is incident on a metal plate, electrons are emitted only when the frequency of the light exceeds a certain threshold frequency

Explain, in terms of energy why this threshold frequency exists.


(b)   A metal plate is illuminated with incident light of frequency x 10 ¹⁴ Hz.
       The maximum kinetic energy of m emitted electron is x 10^-19 J.

calculate:

    (i) the wavelength of the incident light,   x 10 ^-7 m

    (ii) the energy, in J, of each incident photon,   x 10 ^-19 J

    (iii) the work function, in J, of the metal x 10 ^-19 J

    (iv) the work function, in eV, of the metal eV