Suppose that the uncertainty of position of an electron is e
     Suppose that the uncertainty of position of an electron is equal to the radius of the n = 1 Bohr orbit for hydrogen. Calculate the simultaneous minimum uncertainty of the corresponding momentum component, and compare this with the magnitude of the momentum of the electron in the n = 1 Bohr orbit. 
  
  Solution
The radius of the first bohr orbit is x =0.53×10-10m. The uncertainty of the its position is equal to this value
 xp  (1/2).                   ( = h/(2) is reduced Planck constant)
p (1/2) / x
p (1/2)1.0546×10-34 / 0.53×10-10
p 9.94×10-25
momentum of the electron in the first orbit=mv
m= mass of the electron
velocity of electron in the first orbit is v = 2.18x106
P=9.1X10-31X2.18x106
=1.98X0-24

